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Showing 1 - 200 of 3120 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 26, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 90, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 30, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 379, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 26, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 1)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 237, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 10, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 25, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 4, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 5)
Acute Pain     Full-text available via subscription   (Followers: 13)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 7)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 139, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 27, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 4)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 9, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 12, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 23, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 6, SJR: 2.139, h-index: 42)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 4)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 13)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 26, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 9, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 29, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Dermatology     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 12)
Advances in Digestive Medicine     Open Access   (Followers: 7)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 6)
Advances in Drug Research     Full-text available via subscription   (Followers: 23)
Advances in Ecological Research     Full-text available via subscription   (Followers: 47, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 27, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 46, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 52, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Genetics     Full-text available via subscription   (Followers: 17, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 22, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 27)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 10)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 9, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 7)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 1.5, h-index: 62)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.1, h-index: 2)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 370, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 9, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 31, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 16)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 45, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 338, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 9, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 432, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 42, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 56, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 8)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access   (Followers: 1)
Algal Research     Partially Free   (Followers: 9, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 4, SJR: 0.776, h-index: 35)
Alpha Omegan     Full-text available via subscription   (SJR: 0.121, h-index: 9)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 49, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 48, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 48, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 42, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 9, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 26, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 45, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 208, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 61, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 24, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 26, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 36, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 60, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 14)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 4, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 36, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 171, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 8, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 12)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 176, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)

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Journal Cover Algal Research
  [SJR: 2.05]   [H-I: 20]   [9 followers]  Follow
   Partially Free Journal Partially Free Journal
   ISSN (Online) 2211-9264
   Published by Elsevier Homepage  [3123 journals]
  • Non-steroidal anti-inflammatory drugs initiate morphological changes but
           inhibit carotenoid accumulation in Haematococcus pluvialis
    • Authors: István Bácsi; József Deli; Sándor Gonda; Ilona Mészáros; Gréta Veréb; Dalma Dobronoki; Sándor Alex Nagy; Viktória B-Béres; Gábor Vasas
      Pages: 1 - 13
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): István Bácsi, József Deli, Sándor Gonda, Ilona Mészáros, Gréta Veréb, Dalma Dobronoki, Sándor Alex Nagy, Viktória B-Béres, Gábor Vasas
      The economic role of certain types of cysts is unquestionable, since the production of several valuable biomolecules is connected to the resting stages of algae, including the red ketocarotenoid astaxanthin. It is relatively well known, how adverse environmental conditions induce cyst formation and astaxanthin accumulation. In the contrary, there is very limited information about stressors inhibiting these processes. An undesirable consequence of increasing drug use of the human and veterinary medicine is the appearance of the drugs both in natural and in mains water. Therefore, to study the effects of micro-contaminants, e.g. pharmaceuticals to non-target aquatic organisms is a recent issue both from ecological and economical point of view. In this study, the effects of three non-steroidal anti-inflammatory drugs (NSAIDs: diclofenac, diflunisal and mefenamic acid) on growth, cyst formation and astaxanthin accumulation of the flagellated green alga Haematococcus pluvialis were investigated. All three drugs inhibited growth, inhibition ranged from 29 to 81% on the basis of vegetative cell numbers on the 14th day of the experiments. Higher concentrations of the drugs led to higher proportion of cysts, which exceeded 60% of total cell number to the 14th day in diclofenac and diflunisal treatments. On the contrary, astaxanthin contents of treated cultures were lower with the increasing drug concentration, the pigment was undetectable in the presence of 0.075 and 0.05 mg ml−1 diclofenac. Results of carotenoid and chlorophyll content analysis suggest more specific processes behind the observed phenomena than membrane damage. Furthermore, the different phenomena or different extents of the same phenomena suggest that NSAIDs with diverse chemical structures may have different target points in physiological processes. Our results clearly show that NSAIDs could have much wider effective spectra than expected, long-term effects on microalgae might have unexpected ecological or economical consequences due to continuous exposure to these chemicals.
      Graphical abstract image

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.007
      Issue No: Vol. 31 (2018)
  • Potential new genera of cyanobacterial strains isolated from thermal
           springs of western Sichuan, China
    • Authors: Jie Tang; Dong Jiang; Yifan Luo; Yuanmei Liang; Liheng Li; Md. Mahfuzur R. Shah; Maurycy Daroch
      Pages: 14 - 20
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Jie Tang, Dong Jiang, Yifan Luo, Yuanmei Liang, Liheng Li, Md. Mahfuzur R. Shah, Maurycy Daroch
      Cyanobacteria have shown great potential for energy and environmental applications. Cyanobacterial resources, however, are still largely unexplored. Here, forty-nine out of one hundred thirty-two cyanobacterial isolates recovered from thermal springs of western Sichuan, China, were characterized. The phylogenetic analysis of 16S rRNA gene sequences categorized the isolates into three genera, Thermosynechococcus (63.3%), Leptolyngbya (34.7%) and Stanieria (2.0%). Based on sequence similarity, five phylotypes were identified as either putative new species of genus Leptolyngbya or possibly completely new genera. Temperature test showed that all isolates were thermotolerant and twenty-five isolates were capable of growth at temperature of 60 °C, suggesting that these isolates may have strong biotechnological potential. Additionally, three isolates exhibited NaHCO3 tolerance as high as 1 M, indicating that the isolates are promising candidates for bicarbonate-based cyanobacteria production system. Overall, this research laid solid basis for taxonomy and future exploration of extremophilic cyanobacteria for biotechnological and environmental applications.

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2018.01.008
      Issue No: Vol. 31 (2018)
  • Multistage wet lipid extraction from fresh water stressed Neochloris
           oleoabundans slurry – Experiments and modelling
    • Authors: Ying Du; Boelo Schuur; Sascha R.A. Kersten; D.W.F. (Wim) Brilman
      Pages: 21 - 30
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Ying Du, Boelo Schuur, Sascha R.A. Kersten, D.W.F. (Wim) Brilman
      Algae are considered an important renewable feedstock for lipid extraction to produce biofuels. Algae strain Neochloris oleoabundans used in this research can yield a high lipid content under stressed conditions. N-ethyl butylamine (EBA) as a switchable solvent has previously shown outstanding performance on energy efficient lipid extraction from non-broken wet algae slurry. In this work, a model was developed that describes the equilibrium state of lipid extraction from fresh water (FW)-stressed Neochloris oleoabundans algae slurry using EBA as solvent. When assuming that the cell interior is almost completely filled with the solvent phase during extraction, the model estimated extraction yields showed good agreement with those obtained in experiments. The developed model can predict the amount of crude lipid being recovered from any stage of a multistage extraction process.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.001
      Issue No: Vol. 31 (2018)
  • Enhancing fermentation wastewater treatment by co-culture of microalgae
           with volatile fatty acid- and alcohol-degrading bacteria
    • Authors: Wenqiang Qi; Shouhua Mei; Yizhong Yuan; Xuyang Li; Tao Tang; Quanyu Zhao; Minghong Wu; Wei Wei; Yuhan Sun
      Pages: 31 - 39
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Wenqiang Qi, Shouhua Mei, Yizhong Yuan, Xuyang Li, Tao Tang, Quanyu Zhao, Minghong Wu, Wei Wei, Yuhan Sun
      Co-culture of microalgae and bacteria is a promising method for wastewater treatment. The suitable selection of the bacteria in co-cultures with microalgae is critical for wastewater treatment. Three bacteria, Exiguobacterium aurantiacum, Stenotrophomonas acidaminiphila, and Chryseobacterium scophthalmus, were the dominant bacterial species in fermentation wastewater treated by microalgae and activated sludge. Pure cultures and co-cultures of microalgae (Chlorella sorokiniana L3) and these bacteria were evaluated for the treatment of fermentation wastewater, which contains high concentrations of acetate acid, butyric acid, ethanol and butanol. The performance of the co-cultures was better than that of pure cultures of microalgae or bacteria for the removal of four organic compounds, and the removal efficiency of volatile fatty acids and alcohols in the best co-culture case was increased by 22.70% compared to that of pure cultures. Butanol and butyric acid were much more difficult for microalgae and bacteria to remove than were acetic acid and ethanol. The co-cultures of Chlorella sorokiniana L3 with Stenotrophomonas acidaminiphila or Chryseobacterium scophthalmus had the highest removal efficiencies for the four organic compounds in all treatments. The co-cultures of Chlorella sorokiniana L3 with Exiguobacterium aurantiacum, Stenotrophomonas acidaminiphila or Chryseobacterium scophthalmus promoted not only chlorophyll a + b production but also biomass accumulation of Chlorella sorokiniana L3 during the 3 days of cultivation compared with those in pure cultures. More than 77.8% of NH4 +-N, 45.6% of total PO4 3−-P and 63.7% of COD (chemical oxygen demand) were removed in all co-cultures. These three bacteria are potential candidates for wastewater treatment through co-culture with microalgae.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.012
      Issue No: Vol. 31 (2018)
  • Carbon use efficiency diagnostics in Nannochloropsis salina
    • Authors: Tawanda Zidenga; Munehiro Teshima; George Perkins; Thom Rahn; Scott Twary; Jeffrey M. Heikoop
      Pages: 40 - 46
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Tawanda Zidenga, Munehiro Teshima, George Perkins, Thom Rahn, Scott Twary, Jeffrey M. Heikoop
      Carbon dioxide (CO2) can be a significant resource input affecting the cost of algae biomass production on an industrial scale. Improvements in biofuel productivity therefore require characterization of CO2 use efficiency (CUE). RuBisCO saturation with CO2 is an important factor influencing biomass productivity. During CO2 fixation by RuBisCO, fractionation of carbon isotopes occurs, with preferential fixation of 12CO2, resulting in assimilation of the lighter isotope in algae. This photosynthetic discrimination (ΔDIC-algae), approximated by the difference between the δ13C of external medium and that of algae, is a function of the proportion of CO2 fixed relative to supply. ΔDIC-algae has been applied to the study of photosynthesis in algae over the past few decades and we have adopted the tool to characterize improvements in conditions optimized for biofuel productivity, such as controlled photobioreactors. We report the use of ΔDIC-algae as a tool for characterizing CO2 dynamics and RuBisCO saturation in Nannochloropsis salina CCMP 1776, a benchmark strain in algal biofuels research. We use ΔDIC-algae to describe the conditions under which RuBisCO saturation can be achieved to maximize biomass productivity. Our results suggest that determination of ΔDIC-algae can provide important feedback to support engineering and cultural improvements that can impact carbon use efficiency and biomass productivity.

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2018.01.011
      Issue No: Vol. 31 (2018)
  • Cultivation of Emiliania huxleyi for coccolith production
    • Authors: I. Jakob; F. Weggenmann; C. Posten
      Pages: 47 - 59
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): I. Jakob, F. Weggenmann, C. Posten
      Graphical abstract image

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2018.01.013
      Issue No: Vol. 31 (2018)
  • Effect of pulsed electric fields and high pressure homogenization on the
           aqueous extraction of intracellular compounds from the microalgae
           Chlorella vulgaris
    • Authors: Daniele Carullo; Biresaw Demelash Abera; Alessandro Alberto Casazza; Francesco Donsì; Patrizia Perego; Giovanna Ferrari; Gianpiero Pataro
      Pages: 60 - 69
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Daniele Carullo, Biresaw Demelash Abera, Alessandro Alberto Casazza, Francesco Donsì, Patrizia Perego, Giovanna Ferrari, Gianpiero Pataro
      Pulsed Electric Fields (PEF) and High Pressure Homogenization (HPH) are promising and scalable cell disruption technologies of microalgae cells. In this work, the permeabilization degree, morphological properties, and extractability of intracellular compounds from microalgae Chlorella vulgaris suspensions (1.2%, w/w) were investigated as a function of PEF treatment at different electric field strengths (10–30 kV/cm) and total specific energy input (20–100 kJ/kg), in comparison with the more disruptive HPH treatment (150 MPa) at different number of passes (nP = 1–10). The conductivity and the particle size analyses, as well as the SEM images, clearly showed that PEF induces the permeabilization of the cell membranes in an intensity-dependent manner, without producing any cell debris, whereas HPH treatment causes the total disruption of the algae cells into small fragments. Coherently with the lower permeabilization capability, PEF promoted the selective extraction of carbohydrates (36%, w/w, of total carbohydrates), and low molecular weight proteins (5.2%, w/w, of total proteins). On the other hand, HPH induced the undifferentiated release of all the intracellular content, resulting in a 1.1 and 10.3 fold higher yields than PEF, respectively of carbohydrates and protein. These results suggest that, in a multi-stage biorefinery, PEF could represent a suitable cell disruption method for the selective recovery of small-sized cytoplasmic compounds, while HPH should be placed at the end the cascade of operations allowing the recovery of high molecular weight intracellular components.
      Graphical abstract image

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2018.01.017
      Issue No: Vol. 31 (2018)
  • Effect of carbon dioxide on biomass and lipid production of Chlorella
           pyrenoidosa in a membrane bioreactor with gas-liquid separation
    • Authors: Lei Zhang; Yong-Zhong Wang; Shengwei Wang; Ke Ding
      Pages: 70 - 76
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Lei Zhang, Yong-Zhong Wang, Shengwei Wang, Ke Ding
      In this work, an immobilized-cell biofilm photo-bioreactor, in which the CO2-rich gaseous phase was separated from the nutrient-rich liquid phase by a polytetrafluoroethylene membrane, was proposed to enhance the adsorption of CO2 by algal cells and the formation of biofilm on the membrane surface by reducing the disturbance from bubbles. The biomass productivity and biochemical composition, CO2 removal efficiency, and fatty acid profile were measured to evaluate effect of CO2 concentration on biomass and lipid production for biotechnological applications of the photo-bioreactor. The maximal biomass productivity (4.06 g/m2/d), lipid productivity (0.64 g/m2/d), and CO2 removal efficiency (52.5%) were obtained at 3% CO2 concentration, and C16–C18 fatty acids in this cultivated biofilm accounted for 96.28% to 98.61% of the total fatty acids in all runs. The results indicate that the productivities of lipid and biomass were significantly improved using the immobilized-cell cultivation method.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.014
      Issue No: Vol. 31 (2018)
  • Measurement of acoustic properties of microalgae and implications for the
           performance of ultrasonic harvesting systems
    • Authors: Esteban Hincapié Gómez; Jessica Tryner; Alyssa J. Aligata; Jason C. Quinn; Anthony J. Marchese
      Pages: 77 - 86
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Esteban Hincapié Gómez, Jessica Tryner, Alyssa J. Aligata, Jason C. Quinn, Anthony J. Marchese
      Microalgae are a promising feedstock for biofuel production, but difficulties associated with harvesting suspended cultures contribute to the high costs of algal feedstock production. Ultrasonic harvesting has been identified as a potential low-cost technique, but limited data are available on the response of microalgae cells in the presence of an acoustic field. The acoustic radiation force acting on a cell depends upon cell size and the acoustic contrast factor (ACF) of the cell in the media. The ACF depends upon the density and compressibility of the cell and the media. Cell size and ACF were measured for Microchloropsis gaditana, Nannochloropsis oculata, Phaeodactylum tricornutum, and Chlamydomonas reinhardtii. The average ACFs, which were determined by measuring the densities and sound velocities of suspensions containing varying concentrations of cells in growth media, were 0.04 (range = 0.03–0.05) for M. gaditana, 0.02 (range = 0.01–0.04) for N. oculata, 0.05 (range = 0.04–0.07) for P. tricornutum, and 0.05 (range = 0.049–0.053) for C. reinhardtii. The ratio of the acoustic radiation force to the drag force would be highest for C. reinhardtii cells due to their larger effective radius (5.6 μm compared to 1.9–2.7 μm for the other species). The effective ACF of C. reinhardtii was also evaluated by recording the motion of cells in the presence of an acoustic field, using particle tracking velocimetry, and then modeling the recorded motion using COMSOL Multiphysics software. The result (ACF = 0.04) demonstrated agreement with the density/sound velocity meter method. Experiments with starch null sta6 mutant C. reinhardtii cells demonstrated that the effective ACF can transition from positive to zero and eventually become negative as microalgae cells accumulate lipids. The dynamic nature of the ACF represents an opportunity and a challenge for acoustic harvesting of algal cells.
      Graphical abstract image

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.015
      Issue No: Vol. 31 (2018)
  • A pilot-scale bioprocess to produce amphidinols from the marine microalga
           Amphidinium carterae: Isolation of a novel analogue
    • Authors: A. Molina-Miras; A. Morales-Amador; C.R. de Vera; L. López-Rosales; A. Sánchez-Mirón; M.L. Souto; J.J. Fernández; M. Norte; F. García-Camacho; E. Molina-Grima
      Pages: 87 - 98
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): A. Molina-Miras, A. Morales-Amador, C.R. de Vera, L. López-Rosales, A. Sánchez-Mirón, M.L. Souto, J.J. Fernández, M. Norte, F. García-Camacho, E. Molina-Grima
      Marine dinoflagellate microalgae belonging to the genus Amphidinium are a key source of an interesting group of polyketide metabolites with potent bioactivities, wide-ranging functional diversity and stereochemical complexity, but low natural availabilities. The feasibility of a microalgae dinoflagellate-based sustainable bioprocess for producing amphidinols (APDNs) by photoautotrophic culture of Amphidinium carterae in a pilot-scale LED-illuminated bubble column photobioreactor (PBR) was therefore investigated. A fed-batch culture mode with pulse feeding strategy provided a growth pattern strongly limited by the availability of phosphate content in the culture medium that stimulated the production of cellular APDNs. Since A. carterae was found to be much more shear-sensitive than other shear-tolerant non-dinoflagellate microalgae, the culture height and air flow rate were established to ensure the absence of damaging levels of hydrodynamic stress. The biomass capacity yielded by the PBR at the end of the culture (0.540 g d.w. L−1 equivalent to 1.70 × 106 cell mL−1) corresponded to that estimated stoichiometrically from the experimentally determined biomass P-molar formula (C329 O126 H732 N69 S3 P1) and the total phosphorus and nitrogen balances. The downstream processing section was initially conceived to recover APDNs excreted by cells into the supernatant. A dry APDN-enriched extract concentration of 49 mg per liter of supernatant was obtained. This purification process led to partitioning of the extract into several fractions and sub-fractions thereof. Only two sub-fractions were studied, yielding thereof highly pure (>95% pure) luteophanol D and lingshuiol A, and a new, roughly purified (>80% pure) APDN, namely amphidinol 20. The percentages of luteophanol D, lingshuiol A and amphidinol 20 by dry weight of the APDN-enriched extract obtained were 1%, 0.39% and 0.31%, respectively, thus representing a concentration in the culture supernatant of 490, 191 and 152 μg L−1, respectively.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.010
      Issue No: Vol. 31 (2018)
  • Comparative assessment of algal oil with other vegetable oils for deep
    • Authors: Ashish Waghmare; Sonal Patil; Jean Guy LeBlanc; Sachin Sonawane; Shalini S. Arya
      Pages: 99 - 106
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Ashish Waghmare, Sonal Patil, Jean Guy LeBlanc, Sachin Sonawane, Shalini S. Arya
      Algae is an emerging source of vegetable oil. In this study, a comparative assessment of algal oil for deep frying with sunflower and palm oil was performed. Potato sticks were fried for four consecutive days in each of the individual oils under study. These oils were analyzed for density, refractive index, viscosity, oil uptake, acid value, percentage free fatty acid, acidity, peroxide value, total polar compounds, color, radical scavenging activity and fatty acid profile. Fried potato sticks were evaluated for texture and sensorial properties, the latter was performed using a fuzzy logic method. Principle component analysis was done for a variety of physicochemical parameters. This study revealed that the algal oil had the highest physical and chemical stability during the frying process compared to sunflower and palm oils. Potato sticks fried in algal oil had a superior texture and improved sensorial properties. Based on these results it can be concluded that algal oil has a great potential to be used for deep frying foods.

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2018.01.019
      Issue No: Vol. 31 (2018)
  • Energy-efficient outdoor cultivation of oleaginous microalgae at northern
           latitudes using waste heat and flue gas from a pulp and paper mill
    • Authors: Susanne Ekendahl; Mathias Bark; Johan Engelbrektsson; Carl-Anton Karlsson; Domitille Niyitegeka; Niklas Strömberg
      Pages: 138 - 146
      Abstract: Publication date: April 2018
      Source:Algal Research, Volume 31
      Author(s): Susanne Ekendahl, Mathias Bark, Johan Engelbrektsson, Carl-Anton Karlsson, Domitille Niyitegeka, Niklas Strömberg
      Energy efficient cultivation is the major bottleneck for microalgal biomass production on a large scale and considered very difficult to attain at northern latitudes. In this study an unconventional method for industrial microalgae cultivation for bio-oil production using pulp and paper mill waste resources while harvesting only once a year was performed, mainly in order to investigate the energy efficiency of the process. Algae were cultivated for three months in 2014 in covered pond systems with access to flue gas and waste heat from the industry, and the biomass was recovered as thick sediment sludge after dewatering. The cultivation systems, designed to manage the waste resources, reached a promising photosynthetic efficiency of at most 1.1%, a net energy ratio (NER) of 0.25, and a projected year-round energy biomass yield per area 5.2 times higher than corresponding rapeseed production at the location. Thus, microalgae cultivation was, for the first time, proven energy efficient in a cold continental climate. Energy-rich indigenous communities quickly out-competed the oleaginous monocultures used for inoculation. The recovered biomass had higher heating values of 20–23MJkg−1 and contained 14–19% oil dominated by C16 followed by C18 fatty acids. The cultivation season at 59°15′N, 14°18′E was projected to be efficient for 10months and waste heat drying of the biomass is suggested for two winter months. The technique is proposed for carbon sequestering and energy storage in the form of microalgal sludge or dry matter for later conversion into biochemicals.
      Graphical abstract image

      PubDate: 2018-02-14T00:20:43Z
      DOI: 10.1016/j.algal.2017.11.007
      Issue No: Vol. 31 (2018)
  • Biodiversity and distribution of microzooplankton in Spirulina
           (Arthrospira) platensis mass cultures throughout China
    • Authors: Danni Yuan; Xueling Zhan; Mengyun Wang; Xianhui Wang; Weisong Feng; Yingchun Gong; Qiang Hu
      Pages: 38 - 49
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Danni Yuan, Xueling Zhan, Mengyun Wang, Xianhui Wang, Weisong Feng, Yingchun Gong, Qiang Hu
      Spirulina (Arthrospira) platensis is the most commonly produced microalgae for commercial applications, such as nutraceuticals and feed. While crop productivity of commercial Spirulina farms is often compromised by grazers and contaminating microzooplanktons, the biodiversity and identity of the most harmful microzooplanktons in Spirulina farms have not been extensively studied. As China is the number one producer of Spirulina in the world, comprehensive information on the biodiversity and identity of microzooplanktons in Spirulina farms is essential for the long-term commercial viability of these farms. Therefore, we determined the biodiversity and identity of the major microzooplanktons that are present in eight commercial Spirulina cultivation sites throughout China. Furthermore, we identified the major grazers that appear to directly affect the productivity of Spirulina cultures. Among twenty-three species that include 2 flagellates, 2 amoebae, 15 ciliates, and 4 rotifers, Brachionus plicatilis, Frontonia sp. and one unknown Heterolobosean amoeba appeared to be the most harmful to Spirulina due to their high density and ability to graze Spirulina. The similarity of the biodiversity and abundance of the microzooplankton was >80% among two out of eight mass cultivation sites (C and D), while the remaining cultivation sites exhibited their own unique microzooplankton biodiversity characteristics. Redundancy analysis (RDA) showed that there was a positive relationship between harmful species of Brachionus plicatilis and salinity, while the other two harmful species of Heterolobosean amoeba and Frontonia sp. had a positive relationship with oxidation-reduction potential (ORP). As this is the first report to identify the major harmful microzooplankton species in commercial Spirulina farms, our study not only provides a theoretical basis for the relationship between environmental factors and biodiversity of harmful grazers but also lays a scientific foundation for developing effective monitoring and management strategies for commercial Spirulina farms.

      PubDate: 2018-01-02T18:22:24Z
      DOI: 10.1016/j.algal.2017.12.009
      Issue No: Vol. 30 (2018)
  • The fate of nitrogen through algal treatment of landfill leachate
    • Authors: Kaitlyn D. Sniffen; Christopher M. Sales; Mira S. Olson
      Pages: 50 - 58
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Kaitlyn D. Sniffen, Christopher M. Sales, Mira S. Olson
      Nitrogen was tracked though an algae-based landfill leachate remediation system. This system was designed to remove nutrients from the liquid waste via nitrogen assimilation into new algae biomass. While the nitrogen removal pathway of bio-assimilation was present, it was not the only nitrogen removal pathway in the treatment system. Weekly measurements of the dissolved inorganic nitrogen (ammonia-N, nitrate-N, and nitrite-N) and the nitrogen content of the biomass were used to track nitrogen transformation pathways during this yearlong study. During a major part of the study (83.4% of the observed weeks), all nitrogen could not be accounted for in the dissolved inorganic nitrogen or biomass portions of the system. It is hypothesized that some of the unaccounted-for nitrogen was lost due to volatilization of gaseous nitrogen species. Based upon characteristic distribution of measured dissolved inorganic nitrogen and the nitrogen content of the biomass for each week and prior metagenomic analysis of the microbial community in the treatment system, we have postulated potential scenarios of the fate of nitrogen in this algae-based wastewater treatment system. Further research is needed to identify all pathways of nitrogen conversion in algae-based wastewater remediation systems and verify our proposed scenarios.

      PubDate: 2018-01-10T10:44:49Z
      DOI: 10.1016/j.algal.2017.12.010
      Issue No: Vol. 30 (2018)
  • Identification of transcription factors involved in the phenotype of a
           domesticated oleaginous microalgae strain of Tisochrysis lutea
    • Authors: S. Thiriet-Rupert; G. Carrier; C. Trottier; D. Eveillard; B. Schoefs; G. Bougaran; J.-P. Cadoret; B. Chénais; B. Saint-Jean
      Pages: 59 - 72
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): S. Thiriet-Rupert, G. Carrier, C. Trottier, D. Eveillard, B. Schoefs, G. Bougaran, J.-P. Cadoret, B. Chénais, B. Saint-Jean
      Microalgae are an outstanding source of high value products with applications in food, feed or biofuel production. Among these promising organisms, the haptophyte Tisochrysis lutea is commonly used as a feed for shellfish and shrimps in aquaculture. Its capacity to produce high amounts of docosahexanoic acid and storage lipids is also of economic interest for nutrition and energy production. Consequently, understanding its lipid accumulation under nitrogen deprivation is of major interest. Here, we aimed to identify Transcription Factors (TFs) involved in the establishment of the mutant phenotype of the 2Xc1 strain of T. lutea, which accumulates double the quantity of storage lipids under nitrogen deprivation than the wild type strain (WTc1). Strains were grown in chemostats and subjected to different nitrogen availability (limitation, repletion and depletion). Using RNA-seq data, the differentially expressed genes (DEGs) between strains were identified and summarized as a co-expression network to pinpoint putative major TFs in mutant phenotypes. This analysis was followed by a complementary Weighted Gene Correlation Network Analysis in order to classify genes based on their relative importance to mutant phenotype features, regardless of annotation biases due to the lack of functional annotation of the Tisochrysis lutea draft genome. This network-like strategy allowed the identification of seven TF candidates related to key functions in the mutant strain compared with WTc1. In particular, MYB-2R_14 and NF-YB_2 TFs are related to photosynthesis, oxidative stress response and triacylglycerol synthesis. GATA_2, MYB-rel_11 and MYB-2R_20 TFs are likely to be related to nitrogen uptake or carbon and nitrogen recycling, feeding carbohydrate synthesis in the form of chrysolaminarin. Finally, a q-RT-PCR approach further characterized the role of MYB-rel_11 and MYB-2R_20, revealing an expression pattern dependent on nitrogen availability.
      Graphical abstract image

      PubDate: 2018-01-10T10:44:49Z
      DOI: 10.1016/j.algal.2017.12.011
      Issue No: Vol. 30 (2018)
  • Improvement of the seeding of filamentous Ulva tepida on free-floating
    • Authors: Christina Praeger; Rocky de Nys
      Pages: 73 - 78
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Christina Praeger, Rocky de Nys
      A key to the diversification of seaweeds produced in land-based systems is to enable the cultivation of high-value species which require attachment to surfaces. Approaches to enable this have been investigated with the seeding of small floating surfaces, or ‘bioballs’, being successful in an initial proof-of-concept study. The present study improves this method by directly seeding bioballs with U. tepida under aerated outdoor cultivation, thereby eliminating the more complex laboratory-based step, where bioballs are seeded and maintained. This study quantified the effect of density of bioballs in combination with seeding density of zoids on the settlement onto bioballs when seeded under aerated outdoor cultivation. Subsequently, the seeded bioballs were cultivated for 31days to determine growth and productivity, thereby identifying the optimal time point of harvest for maximum productivities. Settlement was significantly affected by the density of zoids and bioballs used during the seeding process, with generally higher numbers of settled zoids on bioballs seeded at high zoid densities in combination with low bioball densities. However, productivity at harvest after 11days onwards was not significantly different across treatments with no carry-over effect from settlement. The highest productivity (12.3±1.8gdwm−2 d−1) was achieved if the bioballs were harvested within 19days of outdoor cultivation and decreased with extended cultivation periods with lower growth rates, and reproductive events on day 27 of outdoor cultivation. Overall, the method significantly improved the baseline method of seeding bioballs by minimising the steps in the seeding and maintenance of bioballs. The requirement of controlled laboratory conditions can be eliminated facilitating scalable on-land production of biomass for bioremediation and bio-products of U. tepida and likely a wider range of seaweed species.

      PubDate: 2018-01-10T10:44:49Z
      DOI: 10.1016/j.algal.2017.12.008
      Issue No: Vol. 30 (2018)
  • The physiology of Chlorella vulgaris grown in conventional and biodigested
           treated vinasses
    • Authors: Camila Candido; Ana Teresa Lombardi
      Pages: 79 - 85
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Camila Candido, Ana Teresa Lombardi
      Conventional and biodigested vinasses are organic and nutrient rich residues from the sugar cane alcohol industry. Their disposal in running waters and soils are controlled due to their eutrophication potential. Using it as algal culture medium, lower costs and residue remediation can be achieved. Here, we report on the physiology of Chlorella vulgaris grown in 60% conventional and 80% biodigested treated vinasses in 6days experiments. Cell densities, chlorophyll a concentrations and pulse amplitude modulated (PAM) fluorometry were used for culture monitoring. Maximum and operational quantum yields, photochemical (qP) and non-photochemical quenchings (qN and NPQ) and rapid light response curves were determined and efficiency of light use (α) and light saturation (IK) obtained for all treatments. The results showed that C. vulgaris grew better in vinasse (1.5–1.6d−1) than in controls (0.9–1.2d−1). PAM fluorometry showed that, despite the increased algal growth in vinasses, photosynthesis was higher in controls than in the residues, supporting that C. vulgaris used organic carbon as energy source. We suggest that the high competitiveness of the microalgae was due to its ability to grow mixotrophically in the residue even though heterotrophic contaminants were present. A reduction of the vinasses eutrophication potential was obtained after the microorganisms' growth. This study is a contribution to the knowledge of microalgae photosynthetic physiology in organic rich residues, information that can help improve algal biomass production in residues at the same time that performs its remediation.

      PubDate: 2018-01-10T10:44:49Z
      DOI: 10.1016/j.algal.2018.01.005
      Issue No: Vol. 30 (2018)
  • An efficient microalgal biomass harvesting method with a high
           concentration ratio using the polymer-surfactant aggregates process
    • Authors: Yin-Hu Wu; Li-Cheng Shen; Hong-Ying Hu; Nick P. Hankins; Wei E. Huang
      Pages: 86 - 93
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Yin-Hu Wu, Li-Cheng Shen, Hong-Ying Hu, Nick P. Hankins, Wei E. Huang
      The high cost and energy consumption related to the downstream harvesting and dewatering process is one of the most important bottlenecks limiting the commercial production of microalgal bioenergy. In this study, a novel microalgal biomass harvesting technique has been developed using polymer surfactant aggregates (PSAs). This approach has been applied to three different microalgal strains and two cynobacterial strains with a recovery efficiency of over 80%. In particular, the recovery efficiency of Chlorella sp. ZTY4 with a biomass concentration of 1.43g·L−1 can be as high as 99.9% using 360mg·L−1 poly (acrylic acid) (PAA) and 4mM (1432mg·L−1) cetylpyridinium chloride (CPC). In addition, with this PAA and CPC dosage, the recovery efficiency of Chlorella sp. ZTY4 remains above 90% for biomass concentrations up to 2.5g·L−1. Furthermore, the water content in the harvested biomass is below 70% with a corresponding concentration ratio of 231. The total flocculation time needed for this technique is 20min. The optimum dosage ratio for PAA to CPC ranges from 90 to 100mg/mmol. Based on these results, an efficient harvesting method with a high concentration ratio is proposed to simplify the whole downstream harvesting and dewatering processes of microalgal biomass.
      Graphical abstract image

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.003
      Issue No: Vol. 30 (2018)
  • Quantification of heterotrophic bacteria during the growth of
           Synechocystis sp. PCC 6803 using fluorescence activated cell sorting and
    • Authors: Yun Zhou; Everett Eustance; Levi Straka; YenJung Sean Lai; Siqing Xia; Bruce E. Rittmann
      Pages: 94 - 100
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Yun Zhou, Everett Eustance, Levi Straka, YenJung Sean Lai, Siqing Xia, Bruce E. Rittmann
      The presence of heterotrophic bacteria in microalgal cultures can dilute the microalgal content of the harvested biomass, compete for nutrients, and be associated with culture crashes. Being able to detect and quantify heterotrophic bacteria would be of high value for monitoring culture health and reducing deleterious effects. Here, we developed and applied a new method that combines flow cytometry (FC) and fluorescence activated cell sorting (FACS) for the quantification of heterotrophic bacteria in cultures of the cyanobacterium Synechocystis sp. PCC 6803. Particles not containing chlorophyll – heterotrophic bacteria and cell debris – were separated from mixed cultures using FACS based on autofluorescence of Synechocystis. Heterotrophic bacteria were differentiated from cell debris using FC with SYTOX green fluorescence. Using microscopy, we verified that FACS was able to quantify heterotrophic bacteria in Synechocystis cultures effectively. Applying these methods to batch cultures of Synechocystis showed that the count proportions of heterotrophic bacteria were significant (3–13%) and that depletion of inorganic P in the culture favored Synechocystis over heterotrophic bacteria, but led to more cell lysis.
      Graphical abstract image

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.006
      Issue No: Vol. 30 (2018)
  • Assessment of genetic and phenotypic diversity of the giant kelp,
           Macrocystis pyrifera, to support breeding programs
    • Authors: Carolina Camus; Sylvain Faugeron; Alejandro H. Buschmann
      Pages: 101 - 112
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Carolina Camus, Sylvain Faugeron, Alejandro H. Buschmann
      The accelerated development of seaweed aquaculture is stimulating research on the genetic drivers of phenotypic diversity of the target species, in order to optimize breeding strategies, to help determine the choice of source populations, and for the selection of traits and varieties that fit with the environmental variability of the production site. This study investigates the spatial variation of the genetic and phenotypic diversities in natural populations of the giant kelp Macrocystis pyrifera, and evaluates the potential for modifying agronomic traits through controlled breeding. Nine microsatellites and 12 morphological traits were used to describe the distribution of diversity present along the Southeastern Pacific (SEP) Coast. We expected concordant patterns of spatial discontinuities if the genetic background was driving morphological divergence across habitats. Crossing experiments were made to assess the heritability of specific traits and evaluate the performance of the F1 generation in the laboratory and in open sea cultivation respectively. Our results revealed four genetic clusters along the latitudinal distribution of M. pyrifera populations, tightly correlated with the existence of major environmental discontinuities. These clusters also matched clusters of morphological diversity, suggesting that both morphological and genetic diversities responded to the same environmental drivers. In crossing experiments, no significant differences were detected between selfed and outbred F1, in morphology, growth and chemical components, but a high variability among all different crosses was observed, revealing a high degree of heritable phenotypic variance. Although, the results suggest that the morphological variation of Macrocystis along the SEP coast is strongly driven by the genetic background. Our controlled crosses were also indicative of a high potential for using this genetic variability in breeding programs for sustainable aquaculture development.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.004
      Issue No: Vol. 30 (2018)
  • Fluorescence activated cell-sorting principles and applications in
           microalgal biotechnology
    • Authors: Hugo Pereira; Peter S.C. Schulze; Lisa Maylin Schüler; Tamára Santos; Luísa Barreira; João Varela
      Pages: 113 - 120
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Hugo Pereira, Peter S.C. Schulze, Lisa Maylin Schüler, Tamára Santos, Luísa Barreira, João Varela
      Microalgal biotechnology has gained increasing attention over the last few decades as a next-generation driver for obtaining food, feed and biofuels and to carry out bioremediation of effluents and CO2 mitigation. Flow cytometry (FC) and fluorescence-activated cell sorting (FACS) have recently acquired outstanding importance in the development of high-throughput methodologies. For example, bioprospecting novel species using FACS widened the current portfolio of available strains for drug discovery and biomass production in large-scale production systems. Moreover, FACS has recently prompted several approaches for the effective improvement of microalgal strains by means of genetic engineering, serial selection and random mutagenesis. In the upcoming years, routine implementation of FC and FACS is expected to further bring forward the field of microalgal biotechnological research as occurred with mammalian cells in biomedical sciences. This review highlights the recent developments of FACS applications to different biotechnological goals, as well as the principles and details of FACS-based microalgal analysis. In addition, the future perspectives of novel and innovative approaches of FACS applications in microalgal biotechnology are suggested and discussed.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2017.12.013
      Issue No: Vol. 30 (2018)
  • Discovery and characterization of Synechocystis sp. PCC 6803
           light-entrained promoters in diurnal light:dark cycles
    • Authors: Allison Werner; Katelyn Oliver; Alexander Dylan Miller; Jacob Sebesta; Christie A.M. Peebles
      Pages: 121 - 127
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Allison Werner, Katelyn Oliver, Alexander Dylan Miller, Jacob Sebesta, Christie A.M. Peebles
      Cyanobacteria are photosynthetic bacteria employed for production of valuable chemicals using sunlight and atmospheric carbon dioxide as substrates. Industrial production in outdoor facilities exposes cyanobacteria to daily light:dark (LD) cycles of sunlight availability. Strain engineers need genetic tools suited for diurnal LD cycles to maximize production in these conditions, but tools for engineering in diurnal LD cycles are extremely limited. Here, we discover native Synechocystis sp. PCC 6803 promoters which provide light-entrained expression in 12-hour light:12-hour dark (12:12) LD cycles. Promoters were characterized using bacterial luciferase bioluminescent promoter probes and RT-qPCR. P hliC , P rbp1 , P slr0006 , and P sigA provide light-entrained expression in 12:12 LD cycles when expressed from the slr0168 chromosomal neutral site. None of the promoters provided free-running oscillations in continuous light (CL) following diurnal LD entrainment, but growth in CL resulted in constant mid-level bioluminescence. Transcripts from P rbp1 , P slr0006 , and P sigA increased significantly following the onset of light, whereas transcripts from P hliC exhibited no oscillations in 12:12 LD cycles. Furthermore, P hliC bioluminescence induction at the onset of light increased at higher light intensities. Overall, our work provides additional genetic engineering tools for cyanobacterial strains for chemical production in diurnal LD cycles.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2017.12.012
      Issue No: Vol. 30 (2018)
  • Potential of intensification techniques for the extraction and
           depolymerization of fucoidan
    • Authors: Noelia Flórez-Fernández; María Dolores Torres; María Jesús González-Muñoz; Herminia Domínguez
      Pages: 128 - 148
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Noelia Flórez-Fernández, María Dolores Torres, María Jesús González-Muñoz, Herminia Domínguez
      Fucoidans are sulfated polysaccharides from brown seaweeds with a variety of biological properties, which are dependent on both their composition and structure, and are determined by the extraction process. The molecular weight of fucoidan, associated with the biological activities and with its bioavailability, can be influenced by the extraction technologies and further depolymerization can be attained during a subsequent processing stage. The conventional technologies for extraction are surveyed and the potential of emerging techniques aiming at enhancing yields, selectivity and bioactivity is discussed.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.002
      Issue No: Vol. 30 (2018)
  • Biomass productivity of native algal communities in Minamisoma city,
           Fukushima Prefecture, Japan
    • Authors: Mikihide Demura; Masaki Yoshida; Akiko Yokoyama; Junko Ito; Hiroshi Kobayashi; Shinji Kayano; Yuichi Tamagawa; Masayuki Watanobe; Naoto Date; Makoto Osaka; Mitsuru Kawarada; Teruo Watanabe; Isao Inouye; Makoto M. Watanabe
      Pages: 22 - 35
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Mikihide Demura, Masaki Yoshida, Akiko Yokoyama, Junko Ito, Hiroshi Kobayashi, Shinji Kayano, Yuichi Tamagawa, Masayuki Watanobe, Naoto Date, Makoto Osaka, Mitsuru Kawarada, Teruo Watanabe, Isao Inouye, Makoto M. Watanabe
      Coastal areas in the Tohoku region were severely damaged by the tsunami that followed the March 2011 earthquake. Consequently, many lands have become non-arable. To assess the use of these non-arable lands for the production of algal biomass, we carried out experimental cultivations of native algal communities in Minamisoma city, Fukushima Prefecture, located in the cool temperate zone of Japan. Productivity of the native algal community was measured using 1-m2 raceway ponds (120L) and open vessel-type bioreactors (50L–500L), with different hydraulic retention times (HRTs) and in the presence or absence of sodium acetate. Maximum productivity in 1-m2 raceway ponds (10-cm water depth) was observed with an HRT of 4days and sodium acetate supplementation in June 2015 (13.2g/m2/day); average productivity throughout the year was 10.6g/m2/day. In the case of deep-water cultivation (80-cm water depth) in vessel-type cultures, the highest productivity (>29g/m2/day) was obtained between January and September 2015. The dominant native microalgal species in the cultivations were Desmodesmus sp. and Scenedesmus acuminatus. Heterotrophic organisms, native bacteria, and protista, such as ciliates and amoeba, were also observed. Species composition and abundance varied depending on the medium content and seasonal conditions.

      PubDate: 2018-01-02T18:22:24Z
      DOI: 10.1016/j.algal.2017.11.008
      Issue No: Vol. 29 (2018)
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30

      PubDate: 2018-02-03T14:13:46Z
  • The impact of wastewater characteristics, algal species selection and
           immobilisation on simultaneous nitrogen and phosphorus removal
    • Authors: Matthew Kube; Bruce Jefferson; Linhua Fan; Felicity Roddick
      Abstract: Publication date: Available online 1 February 2018
      Source:Algal Research
      Author(s): Matthew Kube, Bruce Jefferson, Linhua Fan, Felicity Roddick
      Nutrient removal from wastewater reduces the environmental impact of its discharge and provides opportunity for water reclamation. Algae can accomplish simultaneous nitrogen and phosphorus removal while also adding value to the wastewater treatment process through resource recovery. The application of algae to wastewater treatment has been limited by a low rate of nutrient removal and difficulty in recovering the algal biomass. Immobilising the algal cells can aid in overcoming both these issues and so improve the feasibility of algal wastewater treatment. Trends for nutrient removal by algal systems over different wastewater characteristics and physical conditions are reviewed. The impact that the selection of algal species and immobilisation has on simultaneous nutrient removal as well as the interdependence of nitrogen and phosphorus are established. Understanding these behaviours will allow the performance of algal wastewater treatment systems to be predicted, assist in their optimisation, and help to identify directions for future research.

      PubDate: 2018-02-03T14:13:46Z
      DOI: 10.1016/j.algal.2018.01.009
  • Separation of Chlorella biomass from culture medium by flocculation with
           rice starch
    • Authors: Sook Yan Choy; Krishna Murthy Nagendra Prasad; Ta Yeong Wu; Mavinakere Eshwaraiah Raghunandan; Siew-Moi Phang; Joon Ching Juan; Ramakrishnan Nagasundara Ramanan
      Abstract: Publication date: Available online 4 January 2018
      Source:Algal Research
      Author(s): Sook Yan Choy, Krishna Murthy Nagendra Prasad, Ta Yeong Wu, Mavinakere Eshwaraiah Raghunandan, Siew-Moi Phang, Joon Ching Juan, Ramakrishnan Nagasundara Ramanan
      Coagulation-flocculation remains as one of the preferred methods for efficient harvesting of Chlorella sp. cells. Although the use of established aluminium salts is highly appraised for high harvesting efficiencies, excessive residual aluminium imparted on both the treated supernatant and harvested biomass remained worrisome. Hence, the objective of this present study is to minimize the resulting concentration of aluminium present in the system by evaluating the use of rice starch as an aid to chemical coagulants. The residual aluminium in the starch aided and non-aided treated supernatants and biomass were then determined by using an inductively coupled plasma-optical emission spectroscopy (ICP-OES) and energy-dispersive X-ray (EDX) spectroscopy respectively. At an optimum pH of 6, more than 95% of the initial Chlorella biomass was recovered at 72mg/L of alum or 9mg/L of PACl. However, high residual aluminium contents in treated supernatants (1.3–1.7mg/L) and biomass (2.5–4.5% weight distribution) were evident. Through the introduction of autoclaved rice starch by up to 120mg/L as an aid, the dosage of chemical coagulants applied and the detected residual aluminium concentrations were reduced by up to 54%. Despite the increment in organic loadings for these treated samples, the use of starch which is biodegradable would minimize the resulting toxicity and metal contamination imparted. Thus, rice starch can be considered as a potential alternative to lower the dependence on chemical coagulants which limits the reusability of culture medium. Based on the FE-SEM micrographs obtained, the resulting flocs treated with rice starch were notably filamentous and threadlike; in-line with the coagulation mechanism of adsorption and bridging.

      PubDate: 2018-01-10T10:44:49Z
      DOI: 10.1016/j.algal.2017.11.012
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29

      PubDate: 2018-01-10T10:44:49Z
  • Microfluidic systems for microalgal biotechnology: A review
    • Authors: Hyun Soo Kim; Timothy P. Devarenne; Arum Han
      Abstract: Publication date: Available online 29 December 2017
      Source:Algal Research
      Author(s): Hyun Soo Kim, Timothy P. Devarenne, Arum Han
      Microalgae have a demonstrated potential as producers of high-quality renewable biofuel feedstocks as well as other high-value chemicals. However, significant improvements from microalgal biology and strain development to downstream processing are required to achieve economically viable microalgae-derived biofuels and bioproducts. Mainstream techniques used in microalgal research are based on conventional cell culture and cell handling systems, which are bulky, labor-intensive, time-consuming, and also limited in throughput. Microfluidic lab-on-a-chip systems can offer cost- and time-efficient alternatives to advance microalgal biofuel and bioproduction research by providing high precision and high efficiency cell/reagent handling capabilities, enabling high-throughput assays in a fully automated fashion. Here, we review recent advances in the development and application of microfluidic lab-on-a-chip systems for microalgal biotechnology, especially microalgae-based biofuels, including microsystems for single-cell resolution high-throughput cell identification and separation, highly efficient cell transformation, high-throughput parallel cell cultivation, cell harvesting, and cell analysis applications. Other microfluidic applications such as microalgae-based fuel cells and microalgae-based biosensing platforms are also reviewed towards the end. We conclude by suggesting possible future directions on how microfluidic lab-on-a-chip systems can be utilized to overcome current challenges and improve the current status in microalgal biotechnology.

      PubDate: 2018-01-02T18:22:24Z
      DOI: 10.1016/j.algal.2017.11.020
  • Nitrogen uptake by the macro-algae Cladophora coelothrix and Cladophora
           parriaudii: Influence on growth, nitrogen preference and biochemical
    • Authors: Michael E. Ross; Katharine Davis; Rory McColl; Michele S. Stanley; John G. Day; Andrea J.C. Semião
      Pages: 1 - 10
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Michael E. Ross, Katharine Davis, Rory McColl, Michele S. Stanley, John G. Day, Andrea J.C. Semião
      The capacity of macro-algae to remove nutrients means they have the potential to concomitantly bioremediate polluted waters and generate exploitable biomass. The influence of different nitrogen (N) regimes on growth, biochemical composition and bioremediation capacity was studied for two species of the macro-alga Cladophora. These were incubated in media containing four single N sources, ammonium (NH4 +), nitrite (NO2 −), nitrate (NO3 −) and urea (CO(NH2)2), each with four nitrogen/phosphorous (N/P) ratios, followed by equimolar dual mixtures of these N sources at two selected N/P ratios. There were clear differences in growth between species, depending upon the nutrient regime. In every instance, the daily growth rate (DGR) of Cladophora parriaudii (4.75–11.2%) was higher than that of Cladophora coelothrix (3.98–7.37%) with significance when either NO2 − (p =0.025) or urea (p =0.002) were the employed N form. Differences in algal productivity were reflected in the corresponding N-uptake, whereby C. parriaudii consistently removed more N than C. coelothrix. There were significant differences in growth (p =0.005) when C. parriaudii was cultivated in a single and multi-N source medium: NH4 + was preferentially removed from the medium, whereas urea was typically removed secondarily. However, the presence of urea in the medium enhanced the uptake of the other co-existing N forms and resulted in an increased DGR and yielded a biomass rich in carbohydrates. The relative composition of C. parriaudii varied depending upon N/P ratio of the medium, with the final proportion of protein and carbohydrate ranging from 5 to 15% and 36 to 54% per unit dry weight, respectively. Results from this study demonstrated that algal strain selection is key to treating waste-streams with specific N profiles. Additionally, the biochemical profile of the biomass produced is dependent on the alga and the N regime, providing the potential for designing processes with specific properties and products.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.12.005
      Issue No: Vol. 30 (2017)
  • Comparing EPA production and fatty acid profiles of three Phaeodactylum
           tricornutum strains under western Norwegian climate conditions
    • Authors: Pia Steinrücken; Siv Kristin Prestegard; Jeroen Hendrik de Vree; Julia E. Storesund; Bernadette Pree; Svein Are Mjøs; Svein Rune Erga
      Pages: 11 - 22
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Pia Steinrücken, Siv Kristin Prestegard, Jeroen Hendrik de Vree, Julia E. Storesund, Bernadette Pree, Svein Are Mjøs, Svein Rune Erga
      Microalgae could provide a sustainable alternative to fish oil as a source for the omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, growing microalgae on a large-scale is still more cost-intensive than fish oil production, and outdoor productivities vary greatly with reactor type, geographic location, climate conditions and microalgae species or even strains. The diatom Phaeodactylum tricornutum has been intensively investigated for its potential in large-scale production, due to its robustness and comparatively high growth rates and EPA content. Yet, most research have been performed in southern countries and with a single commercial P. tricornutum strain, while information about productivities at higher latitudes and of local strains is scarce. We examined the potential of the climate conditions in Bergen, western Norway for outdoor cultivation of P. tricornutum in flat panel photobioreactors and cultivated three different strains simultaneously, one commercial strain from Spain (Fito) and two local isolates (M28 and B58), to assess and compare their biomass and EPA productivities, and fatty acid (FA) profiles. The three strains possessed similar biomass productivities (average volumetric productivities of 0.20, 0.18, and 0.21gL−1 d−1), that were lower compared to productivities reported from southern latitudes. However, EPA productivities differed between the strains (average volumetric productivities of 9.8, 5.7 and 6.9mgL−1 d−1), due to differing EPA contents (average of 4.4, 3.2 and 3.1% of dry weight), and were comparable to results from Italy. The EPA content of strain Fito of 4.4% is higher than earlier reported for P. tricornutum (2.6–3.1%) and was only apparent under outdoor conditions. A principal component analysis (PCA) of the relative FA composition revealed strain-specific profiles. However, including data from laboratory experiments, revealed more significant differences between outdoor and laboratory-grown cultures than between the strains, and higher EPA contents in outdoor grown cultures.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.12.001
      Issue No: Vol. 30 (2017)
  • Direct effects of ulvan and a flour produced from the green alga Ulva
           fasciata Delile on the fungus Stemphylium solani Weber
    • Authors: Renata Perpetuo Reis; Aníbal Alves de Carvalho Junior; André Pellicciotta Facchinei; Ana Carolina dos Santos Calheiros; Beatriz Castelar
      Pages: 23 - 27
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Renata Perpetuo Reis, Aníbal Alves de Carvalho Junior, André Pellicciotta Facchinei, Ana Carolina dos Santos Calheiros, Beatriz Castelar
      Alternative methods of fungal biocontrol are required, and this paper looks at natural sources of products which can be produced and used without significant risk to human health and the environment, thereby reducing the need for toxic pesticides. Even after the significant expenditures on agrochemical control agents, a significant fraction of agriculture production is regularly lost due to fungal diseases. Species of Ulva are known to produce bioactive substances that can induce plant resistance to diseases. Before committing to the extensive use of extracts from such algal sources as elicitors in agriculture, it is essential to confirm the specificity of their antifungal activities. This study, examined whether extracts and dried, milled flour of Ulva fasciata demonstrated antifungal activity against the commercially important pathogen, Stemphylium solani. Samples of S. solani were obtained from infected leaves of the tomato Solanum lycopersicum and were cultured on Potato-Dextrose-Agar medium, with three added concentrations of ulvan and flour obtained from U. fasciata (0.1; 0.5 and 1.0g·L−1), in a BDO chamber, at 25°C, for 10days in the dark. The diameter of the mycelia was used as the parameter for fungal growth. Neither the flour nor ulvan from U. fasciata showed any direct anti-fungal activity, but the presence of compounds produced by U. fasciata showing antagonist physiological effects against S. solani should be investigated.

      PubDate: 2017-12-26T18:17:05Z
      DOI: 10.1016/j.algal.2017.12.007
      Issue No: Vol. 30 (2017)
  • Isolation and biochemical characterisation of two thermophilic green algal
           species- Asterarcys quadricellulare and Chlorella sorokiniana, which are
           tolerant to high levels of carbon dioxide and nitric oxide
    • Authors: Prachi Varshney; John Beardall; Sankar Bhattacharya; Pramod P. Wangikar
      Pages: 28 - 37
      Abstract: Publication date: March 2018
      Source:Algal Research, Volume 30
      Author(s): Prachi Varshney, John Beardall, Sankar Bhattacharya, Pramod P. Wangikar
      Atmospheric levels of carbon dioxide (CO2) and nitric oxide (NO) have been on the rise ever since the beginning of industrialisation. A significant fraction of this increase can be attributed to the emissions from stationary sources such as thermal power plants and steel plants. While there has been an impetus in recent times towards sequestration of these greenhouse gases at source, current technologies are not commercially viable. In this context, microalgae-mediated CO2 capture and utilization has attracted attention, although several technological challenges remain to be addressed. Importantly, this process will require algal strains that grow fast and are tolerant to high light, temperature and flue gases. The majority of the reported algal strains fail in at least one of these requirements. On account of this, we have isolated two novel green algal strains, which have been identified as Asterarcys quadricellulare and Chlorella sorokiniana, from water bodies that are located in and around a steel plant in India. These are relatively fast-growing strains with specific growth rates of up to 0.06h−1 and 0.1h−1, respectively. Furthermore, these strains can tolerate high temperatures of up to 43°C, high light intensity and high CO2 and NO levels. When exposed to high CO2 levels, 55–71% of the dry cell weight comprised of carbohydrates. Additionally, exposure to NO gas along with CO2 led to an enhanced lipid accumulation of 44%–46% of dry biomass. The high lipid content makes these strains valuable feedstock in biodiesel production, and the high carbohydrate content makes the lipid extracted biomass an attractive source of carbon for biochemical conversion to ethanol. We believe that these strains are promising and ready to be tested with real flue gases under outdoor conditions.

      PubDate: 2017-12-26T18:17:05Z
      DOI: 10.1016/j.algal.2017.12.006
      Issue No: Vol. 30 (2017)
  • Draft genomes and phenotypic characterization of Tisochrysis lutea
           strains. Toward the production of domesticated strains with high added
    • Authors: Gregory Carrier; Caroline Baroukh; Catherine Rouxel; Laëtitia Duboscq-Bidot; Nathalie Schreiber; Gaël Bougaran
      Pages: 1 - 11
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Gregory Carrier, Caroline Baroukh, Catherine Rouxel, Laëtitia Duboscq-Bidot, Nathalie Schreiber, Gaël Bougaran
      Tisochrysis lutea is a microalga species currently used in aquaculture as a feed for shellfish, oysters and shrimps. It also has many other potential industrial applications, such as the production of neutral lipids for biofuels or the production of ω-3 fatty acids for nutraceuticals (human food complements). To efficiently exploit the potential of this microalga, however, higher lipid productivities are needed. To this end, improvement programs need to be developed and optimized. The diversity of strains available in microalgae has not yet been exploited in such improvement programs. In this study, the intra-strain diversity was observed and exploited to increase neutral lipid productivity. New clonal strains with higher neutral lipid productivity were successfully selected. The best clonal strain selected accumulated 520% more triacylglycerols, with a similar growth rate to the wild-type strain in continuous light and nitrogen starvation conditions. In a photoperiod culture condition, this clonal stain also accumulated 84% more storage lipids and 30% less carbohydrates, compared to the wild-type strain. This clonal strain thus had a higher productivity which is of great interest for feed or biofuel applications. This study also focused on identifying the genomic mechanisms responsible for the improvements in these clonal strains. With this objective, the genome of Tisochrysis lutea was sequenced for the first time. It is the third genome of a Haptophyte microalga sequenced so far. Different genetic polymorphisms were identified between the sequenced genomes of the wild-type strain and clonal strains. Activity of transposable elements seems to have been involved in the genome reshuffling obtained through the improvement program. The contribution of transposable elements to the adaptive capacity of microalgae remains to be demonstrated.
      Graphical abstract image

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.10.017
      Issue No: Vol. 29 (2017)
  • The effect of different light regimes on diatom frustule silicon
    • Authors: Yanyan Su; Nina Lundholm; Marianne Ellegaard
      Pages: 36 - 40
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Yanyan Su, Nina Lundholm, Marianne Ellegaard
      Significant changes in frustule morphology of Coscinodiscus granii induced by different light regimes have previously been observed, but whether these changes are companied by similar changes in cellular silicon concentration or are solely due to reorganization is unknown. The influence of six different light regimes, blue (B), green (G), yellow (Y), red-orange (RO), red (R) and white (W), at two intensities (100 and 300μmolphotonsm−2 s−1) on cellular silicon content was therefore assessed for C. granii. Both the cellular Si content and the Si concentration per surface area were higher at 300 than at 100μmolphotonsm−2 s−1 for all tested wavelengths, except Y light. At the same light intensity, cells grown at B light had the highest cellular Si content (except W at 300μmolphotonsm−2 s−1) and Si concentration per surface area. At R, OR, G, B and W light, high intensity led to higher cellular Si content although the mean frustule size was smaller (opposite for Y light). As the higher Si content was not due to a larger cell size, we hypothesize that the effect is due to changes in valve thickness. The underlying adaptive significance of this phenomenon might be that at low irradiance (100μmolphotonsm−2 s−1), diatom buoyancy is modulated by accumulating less silicon in the cells, as the less silicified cells may have lower sinking rate and thus remain longer at the higher light in the upper part of the water column, which could partly contribute to the ecological success of the diatom.

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.014
      Issue No: Vol. 29 (2017)
  • An investigation into the effect of culture conditions on fucoxanthin
           production using the marine microalgae Phaeodactylum tricornutum
    • Authors: Dale D. McClure; Audrey Luiz; Blandine Gerber; Geoffrey W. Barton; John M. Kavanagh
      Pages: 41 - 48
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Dale D. McClure, Audrey Luiz, Blandine Gerber, Geoffrey W. Barton, John M. Kavanagh
      Fucoxanthin is a carotenoid pigment produced by algae that has a range of potential health benefits. Despite the obvious interest in developing a process for the production of fucoxanthin, relatively few authors have systematically examined the impact of culture conditions (i.e. the light intensity, medium composition and CO2 addition) on fucoxanthin production. In this work, we have addressed this issue using the marine microalgae Phaeodactylum tricornutum. It was found that at low light intensities (100μmol photons m−2 s−1) the specific fucoxanthin concentration was greater (42.8±19.5mgg−1) than at a higher intensity of 210μmol photons m−2 s−1 (9.9±4.2mgg−1). Addition of nitrate to the medium led to a significant increase in the specific fucoxanthin concentration with the maximum specific concentration (59.2±22.8mgg−1), volumetric concentration (20.5mgL−1) and bioreactor productivity (2.3mgL−1 day−1) being observed with the nitrate enriched medium. These reproducible results from our systematic investigation into the effect of culture conditions on fucoxanthin production are highly encouraging and clearly demonstrate the potential for P.tricornutum to be employed as a natural source of fucoxanthin in nutraceutical applications.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.015
      Issue No: Vol. 29 (2017)
  • Poly-β-hydroxybutyrate (PHB) production by Synechocystis PCC6803 from
           CO2: Model development
    • Authors: Roberta Carpine; Francesca Raganati; Giuseppe Olivieri; Klaas J. Hellingwerf; Antonino Pollio; Piero Salatino; Antonio Marzocchella
      Pages: 49 - 60
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Roberta Carpine, Francesca Raganati, Giuseppe Olivieri, Klaas J. Hellingwerf, Antonino Pollio, Piero Salatino, Antonio Marzocchella
      The biosynthesis of poly-β-hydroxybutyrate (PHB) by bioconversion of CO2 is a sustainable alternative to the non-renewable, petroleum-based polymer production. Indeed, the PHB production by conversion of CO2 contributes to the reduction of the greenhouse-gas concentration in the atmosphere. A kinetic dynamic model of PHB production by autotrophic cultures of Synechocystis PCC6803 was proposed and developed by means of the biochemical networks simulator COPASI. Two classes of cells were assumed to be present in the broth: growing cells, PHB producing cells. The model included the two classes of cells and their nitrogen and phosphate internal quota. The dynamics of the cell growth and PHB production were described taking into account: cellular growth rate; lysis rate; nitrate and phosphate utilization rate; PHB production rate. The assessment of the kinetic parameters and of the yields (model calibration) was carried out by the regression of experimental data. Tests were carried out in photobioreactors under dynamic light system (light/dark cycle) using media characterized by initial nitrate concentration ranging between 0 and 1.5g/L. The developed model was validated with respect to independent experimental set. The proposed model successfully reproduced the experimental data (cell concentration, nitrogen and phosphate concentration and PHB content): the square correlation coefficient of the investigated variable concentrations ranged between 0.81 and 0.99. Parameter sensitivity analysis was carried out to assess the role of the selected parameters on cell growth and PHB accumulation. The dynamics of cellular growth were not significantly affected by a ±20% variation of maximum specific growth rate, of velocity of conversion to PHB producing cells, and of maximum uptake rate of nitrate. The PHB accumulation dynamics were particularly sensitive to the variation of the value of the investigated parameters. The proposed model may support the design and the optimization of a PHB production process by means of autotrophic cultures.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.011
      Issue No: Vol. 29 (2017)
  • Keeping the light energy constant — Cultivation of Chlorella sorokiniana
           at different specific light availabilities and different photoperiods
    • Authors: Claudia Holdmann; Ulrike Schmid-Staiger; Helena Hornstein; Thomas Hirth
      Pages: 61 - 70
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Claudia Holdmann, Ulrike Schmid-Staiger, Helena Hornstein, Thomas Hirth
      Microalgae cultivation is strongly dependent on light availability. Sunlight is the natural energy source for algae cultivation processes, but its fluctuation during the day and the natural day-night-rhythm mean an increasing challenge for an efficient algae production. Additionally, different seasons lead to unequal photoperiods and their influence on the productivity has not been determined in detail yet. Therefore, we investigated the growth of Chlorella sorokiniana at different light intensities and illumination cycles of 24h/0h (light/dark), 16/8h and 12/12h. The light integral, more exactly the amount of photons per gram biomass and day (specific light availability) was kept constant during 24h to ensure the comparability of the results of the different photoperiods. During the cultivation in repeated fed-batch mode, the productivity and biomass yield on light of Chlorella sorokiniana were determined to characterize the growth. During the night phase a biomass loss occurred, which was independent of the night temperature and the specific light availability on the day before, but increased with higher biomass concentration. A higher biomass yield on light during the shorter photoperiods led to an improved gross productivity compared to the continuous illumination, especially at a biomass concentration above 4gL−1. This compensated for the night loss; therefore, the net productivity (during one day) was independent of the photoperiod. In order to determine an optimal process window biomass yield on light and productivity have to be considered. They are diametric with respect to the specific light availability and furthermore dependent on the biomass concentration. The optimal combination of biomass yield on light and productivity could be achieved with a biomass concentration below 4gL−1 during 24/0 illumination and with a biomass concentration below 7gL−1 during shorter photoperiods; the specific light availability should be as high as possible.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.005
      Issue No: Vol. 29 (2017)
  • Economical DHA (Docosahexaenoic acid) production from Aurantiochytrium sp.
           KRS101 using orange peel extract and low cost nitrogen sources
    • Authors: Won-Kun Park; Myounghoon Moon; Sung-Eun Shin; Jun Muk Cho; William I. Suh; Yong Keun Chang; Bongsoo Lee
      Pages: 71 - 79
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Won-Kun Park, Myounghoon Moon, Sung-Eun Shin, Jun Muk Cho, William I. Suh, Yong Keun Chang, Bongsoo Lee
      The commercial production of microalgae-derived docosahexaenoic acid (DHA) has been expanding due to several advantages of algal over fish oil produced DHA. While the DHA production technology from microalgae is already economically competitive, alternatives to pure glucose and yeast extract still need to be explored to reduce the costs and increase the profits further. In the present study, orange peel waste (OPW) and various nitrogen sources were investigated as alternative nutrient sources for the economic cultivation of Aurantiochytrium sp. KRS101. The utilization of orange peel extract (OPE) supplemented with NaNO3 showed a higher DHA yield than that supplemented with NH4Cl or urea, and pH5.5 was found to be the optimum initial condition for Aurantiochytrium sp. KRS101. OPE optimized with supplemental NaNO3 (1.2g/L) resulted in a DHA yield of 0.63g/L, which was 2.5 fold greater than the yield obtained using a conventional basal medium containing a similar amount of total nitrogen and 67% greater total carbon sources. This result implied not only that the conventional use of glucose and yeast extract have lower efficiency levels during nutrient metabolism but also that the types of carbon and nutrient sources have a significant effect on the DHA yield. The addition of supplemental glucose further enhanced the biomass, fatty acid methyl esters (FAME), and DHA yields, which unveiled the high C:N ratio requirement of Aurantiochytrium sp. KRS101. These results suggest that the development and optimization of microalgae fermentation using OPE and NaNO3 is a possible route for the economical production of DHA and for the additional utilization of food waste.
      Graphical abstract image

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.017
      Issue No: Vol. 29 (2017)
  • Comparative transcriptome analysis between heat-tolerant and sensitive
           Pyropia haitanensis strains in response to high temperature stress
    • Authors: Wenlei Wang; Yinghui Lin; Fei Teng; Dehua Ji; Yan Xu; Changsheng Chen; Chaotian Xie
      Pages: 104 - 112
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Wenlei Wang, Yinghui Lin, Fei Teng, Dehua Ji, Yan Xu, Changsheng Chen, Chaotian Xie
      Pyropia haitanensis farms in South China often suffer from sustained high temperatures in autumn, which is the early seeding period, resulting in disease, premature senility, and eventual decay, ultimately leading to a substantial reduction in yield. However, the molecular mechanisms underlying the response to high temperature stress in P. haitanensis remain unknown. In the present study, we used the Illumina sequencing platform to examine the transcriptional profiles of heat-tolerant (THT) and heat-sensitive (WHT) P. haitanensis strains exposed to different durations of high temperature stress. THT exhibited more differentially expressed genes and greater fold-changes in transcripts under sustained temperature stress, suggesting that this strain is better able to increase transcriptional regulation in response to high temperature stress than WHT. Furthermore, heat stress induced different expression patterns in the thalli of the two strains. THT was able to maintain or increase the activities of energy metabolism, antioxidant systems, and phosphatidylinositol signal transduction to resist heat stress, while these processes were dramatically reduced in WHT, resulting in the thalli being unable to survive under sustained high temperatures. The present data provide a better understanding of the mechanisms underlying the response of P. haitanensis to high temperature stress, which may facilitate the development of technologies and breeding strategies for improving thermotolerance in Pyropia.

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.026
      Issue No: Vol. 29 (2017)
  • Diurnal variation of various culture and biochemical parameters of
           Arthrospira platensis in large-scale outdoor raceway ponds
    • Authors: Nora Hidasi; Amha Belay
      Pages: 121 - 129
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Nora Hidasi, Amha Belay
      The use of microalgae for nutraceuticals, food, and feed has recently gained great interest. Having a good understanding of the trends, including the diurnal variations, of the physiological parameters and biochemical composition of the biomass in commercial scale systems is of high importance as it may lead to finding potential ways to optimize productivity and product quality. Not much is known about the diurnal variation of the physiological parameters and biochemical composition of microalgae grown in large-scale outdoor raceway ponds in general and Arthrospira in particular, even though a lot is known about such diurnal variations in natural aquatic and laboratory environments. Arthrospira (Spirulina) platensis is a filamentous cyanobacterium widely used as dietary supplement, functional food, food, and animal feed. It has been grown commercially for about 40years. In the present experiments the diurnal variation of some photosynthetic parameters and of the product quality was studied in Arthrospira platensis grown outdoors in a 5000m2 raceway pond over a 24-hour period at three different months of the year. Specific trends for Arthrospira in commercial scale setup were described for the first time. Significant variation was observed in the biomass composition throughout the course of the day. The photosynthetic pigment content of Arthrospira (chlorophyll a, total carotenoids, and total phycocyanin) declined during the light hours, and recovered during the night. The same pattern was seen in the case of the crude protein content of the biomass. The total carbohydrate content however showed an opposite trend to that of the protein. Selected parameters were simulated in the lab in benchtop photobioreactors and the trends were compared with the large-scale system. The results of the experiments are discussed in relation to diurnal changes in some physical and chemical factors.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.08.027
      Issue No: Vol. 29 (2017)
  • Identification and feeding characteristics of the mixotrophic flagellate
           Poterioochromonas malhamensis, a microalgal predator isolated from outdoor
           massive Chlorella culture
    • Authors: Mingyang Ma; Yingchun Gong; Qiang Hu
      Pages: 142 - 153
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Mingyang Ma, Yingchun Gong, Qiang Hu
      Chlorella is a strong candidate as a potential production organism for future biofuels and other algal-derived products, but contamination by grazing protozoa is a major constraint to its commercial production on a large scale. In this study, a mixotrophic flagellate chrysophyte that targeted Chlorella in mass culture was observed in samples from outdoor massive photobioreactor systems. Data from field studies demonstrated that once the predatory flagellate was observed in the algal culture, there was a dramatic reduction in Chlorella cell concentration. The grazer was identified as Poterioochromonas malhamensis, based on both morphology and molecular barcoding employing 18S rDNA gene sequences. Transmission electron microscopy revealed that P. malhamensis digested the ingested Chlorella sorokiniana cells within a food vacuole, with residual cell wall from the prey being observed in the final phase. It was noted that during the process of ingesting and digesting the C. sorokiniana cells, the chloroplast of P. malhamensis reduced in size, whereas the number and volume of mitochondria increased. After the prey had been completely digested, the chloroplast and mitochondria of P. malhamensis returned to their pre-feeding status. Feeding experiments in the laboratory demonstrated that cell concentrations of C. sorokiniana and P. malhamensis were negatively correlated. Furthermore, once P. malhamensis reached 5×105 cellsmL−1 and the ratio of C. sorokiniana to P. malhamensis was in the range 15:1 to 30:1, the cell concentration of the C. sorokiniana culture decreased dramatically. The optimal temperature for P. malhamensis grazing on C. sorokiniana was 25°C; the grazing ability of P. malhamensis in light conditions was higher than that in dark conditions; and P. malhamensis preferred weakly acidic conditions. In addition, it was demonstrated that this flagellate could graze on other common microalgae of commercial value. On the basis of its capacity to ingest a wide spectrum of phytoplankton, and its wide environmental range and global distribution, this contaminant has the potential to be a common problem in microalgal mass cultures and warrants further study.

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.024
      Issue No: Vol. 29 (2017)
  • Effect of light spectrum on isolation of microalgae from urban wastewater
           and growth characteristics of subsequent cultivation of the isolated
    • Authors: Mahsa Izadpanah; Reza Gheshlaghi; Mahmood Akhavan Mahdavi; Ali Elkamel
      Pages: 154 - 158
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Mahsa Izadpanah, Reza Gheshlaghi, Mahmood Akhavan Mahdavi, Ali Elkamel
      Light quality plays an important role in regulation of microalgae growth. The aim of this work was to investigate the role of light spectrum in isolation of different strains of microalgae from urban wastewater. Screening and isolation under three light spectrums of white, red, and blue resulted in three different strains of Chlorella sorokiniana IG-W-96, Chlorella vulgaris IG-R-96, and Chlorella sp. IG-B-96, respectively. The strains were identified and named based on morphological characterization under light and confocal microscopy followed by molecular characterization. It was revealed that the light spectrum had significant influence on microalgae cell size. The largest and smallest cells were observed under blue and red light, respectively. The isolated strain under blue light when subsequently cultured under blue light in suspension mode showed the highest biomass density of 1.21±0.00gl−1, as well as lipid density and productivity of 0.29±0.02gl−1 and 40.24±4.02mglipid l−1 day−1, respectively. Due to its shorter growth time, however, maximum biomass productivity was obtained for the isolated and cultured strain under red lights. The proposed illumination methodology in isolation and cultivation improved growth characteristics, in such a way that similar light spectra in both steps led to the highest amounts of biomass, lipid, and productivities for each strain.

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.029
      Issue No: Vol. 29 (2017)
  • Enhanced hydrocarbon production and improved biodiesel qualities of
           Botryococcus braunii KMITL 5 by vitamins thiamine, biotin and cobalamin
    • Authors: Suneerat Ruangsomboon; Piyanuch Sornchai; Noratat Prachom
      Pages: 159 - 169
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Suneerat Ruangsomboon, Piyanuch Sornchai, Noratat Prachom
      Botryococcus braunii, a green microalga which is a potentially good biodiesel feedstock, was isolated from a freshwater fish pond in Bangkok, and the effects of B-vitamins—thiamine, biotin and cobalamin as well as their mixes—on its biomass, hydrocarbon production, carbohydrate content and biodiesel properties were investigated, using a control group that was not supplemented with any vitamins. The addition of thiamine increased the alga's biomass and hydrocarbon content, whereas addition of biotin, cobalamin and mixes of all three vitamins did not increase its hydrocarbon content. Among the vitamins tested, thiamine 150μgL−1 was the best for producing high biomass (2.08±0.07gL−1), hydrocarbon content (37.29±0.41%), hydrocarbon yield (0.77±0.03gL−1) and hydrocarbon productivity (90.32±3.05mgL−1 d−1). Maximum carbohydrate content (386±39mgg−1) was achieved by addition of 1μgL−1 cobalamin. Compared to the control group, the alga cultured in media supplemented with 100μgL−1 thiamine showed better biodiesel properties with lower iodine value (76.42g I2 100g−1), cold filter plugging point (9.90°C) and higher cetane number (54.30). Therefore, thiamine was shown to be a promising culture medium supplement for this strain for using it as a feedstock for biodiesel production. An investigation of vitamin B-related gene in B. braunii KMITL 5 found related genes for thiamine (thi), biotin (bioB and bioF) and cobalamin (metE and metH) vitamins, which are marks of vitamin autotrophy in algae.

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.028
      Issue No: Vol. 29 (2017)
  • Assessing textile wastewater treatment in an anoxic-aerobic
           photobioreactor and the potential of the treated water for irrigation
    • Authors: Zaineb Dhaouefi; Alma Toledo-Cervantes; Dimas García; Ahmed Bedoui; Kamel Ghedira; Leila Chekir-Ghedira; Raúl Muñoz
      Pages: 170 - 178
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Zaineb Dhaouefi, Alma Toledo-Cervantes, Dimas García, Ahmed Bedoui, Kamel Ghedira, Leila Chekir-Ghedira, Raúl Muñoz
      The potential of an anoxic-aerobic photobioreactor for the treatment of synthetic textile wastewater (STWW) was evaluated in terms of carbon and nutrient removal, water and toxicity reduction. The potential of the treated water for irrigation of Raphanus sativus was also assessed. Despite the low C/N ratio of the STWW, microalgae-bacteria symbiosis supported steady-state removal efficiencies of total organic carbon, total nitrogen and total phosphorus of 48±3%, 87±11% and 57±5%, respectively, at a hydraulic retention time of 10days. In addition, a consistent decolorization of the STWW was observed, with disperse orange-3 and blue-1 removals of ~80% and ~75%, respectively. This effective STWW treatment was confirmed by the reduction in genotoxicity potential and enhanced growth of R. sativus during irrigation with treated water. Finally, the heavy metal content of the soils irrigated with treated water was lower than that of STWW irrigated soils, which highlights the potential of this anoxic-aerobic photobioreactor for the treatment of textile wastewater and water reuse. However, more studies are still needed to elucidate the long-term effects of the treated water over the final consumer health.
      Graphical abstract image

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.032
      Issue No: Vol. 29 (2017)
  • Exploring the function of acyltransferase and domain replacement in order
           to change the polyunsaturated fatty acid profile of Schizochytrium sp.
    • Authors: Lu-jing Ren; Sheng-lan Chen; Ling-jun Geng; Xiao-jun Ji; Xian Xu; Ping Song; Song Gao; He Huang
      Pages: 193 - 201
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Lu-jing Ren, Sheng-lan Chen, Ling-jun Geng, Xiao-jun Ji, Xian Xu, Ping Song, Song Gao, He Huang
      Omega-3 fatty acids have received considerable attention due to their substantial health benefits. The aim of this study was to investigate the roles of acyltransferase (AT) domain and replace it for regulating fatty acid profile in Schizochytrium sp.. Herein, Schizochytrium sp. was engineered via gene deletion of AT and replacement of the native AT with its homologue, Shew-AT domain from Shewanella sp.. The docosahexaenoic acid (DHA) content in total fatty acids of the AT deficient strain observably decreased from 49.52% to 35.2% and the strain exhibited a low growth rate. Replacement with the Shew-AT gene recovered the cell growth and led to a high DHA content, with 3.7 times more eicosapentaenoic acid (EPA). This study will expand knowledge for synthesis of polyunsaturated fatty acid and facilitate the design of microbes with high yields of omega-3 fatty acids as a source of these valuable compounds for nutritional improvement.
      Graphical abstract image

      PubDate: 2017-12-09T03:51:12Z
      DOI: 10.1016/j.algal.2017.11.021
      Issue No: Vol. 29 (2017)
  • Marine integrated pest management (MIPM) approach for sustainable
    • Authors: Kapilkumar Nivrutti Ingle; Mark Polikovsky; Alexander Chemodanov; Alexander Golberg
      Pages: 223 - 232
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Kapilkumar Nivrutti Ingle, Mark Polikovsky, Alexander Chemodanov, Alexander Golberg
      Seaweed farming, or seagriculture, is expected to provide sustainable biomass enabling the development of marine bioeconomy through the blue growth. Epiphytism is a common phenomenon in seaweed farming that impacts the biomass yield. Epiphytes may be other non-wanted algal species, viruses, bacteria, and fungi. Epiphytes can attract grazers such as crabs, lobsters, shrimp, crayfish, fish, and turtles, which have both positive (enriched biodiversity throughout the food chain, ecosystem services, etc.) and negative (yield loss, etc.) impacts on seaweed farming. A critical challenge for the future seagriculture is how to address the pest problem. Although well developed for terrestrial agriculture, pest management frameworks for seaweed farming have yet to be set up. In this regard, we propose a framework for marine integrated pest management in seaweed farming. Based on several cases-studied: indoor and offshore seaweed farming in Israel and traditional seaweed farming in India, pest prevention, pest control, pest mitigation strategies and their implementations are discussed.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.010
      Issue No: Vol. 29 (2017)
  • Elucidating the Cronbergia (cyanobacteria) dilemma with the description of
           Cronbergia amazonensis sp. nov. isolated from Solimões river (Amazonia,
    • Authors: Diego Bonaldo Genuário; Célia Leite Sant'Anna; Itamar Soares Melo
      Pages: 233 - 241
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Diego Bonaldo Genuário, Célia Leite Sant'Anna, Itamar Soares Melo
      The settlement of the genus Cronbergia as novel taxa has been frequently questioned among cyanobacterial taxonomists. Its validity is uncertain mainly because of the high similarity (97.4%) found between the 16S rRNA gene sequences of the type-species Cronbergia siamensis SAG 11.82 and Cylindrospermum stagnale PCC7417, despite their substantial morphological differences. In the present study, one filamentous heterocytous cyanobacterial strain isolated from the Solimões river (Brazilian Amazonia) was studied in detail by means of morphology and molecular phylogeny as well by ITS (internal transcribed spacer) secondary structures. According to the results, this novel strain showed all the morphological features recognized for the Cronbergia genus and its 16S rRNA gene sequence clustered with C. siamensis SAG 11.82, leading to the description of C. amazonensis as a novel species. However, this cluster did not group to the 16S rRNA gene sequence used in the description of the genus Cronbergia. Additionally, this study demonstrated the existence of multiple 16S rRNA gene sequences retrieved from the type-species, Cronbergia siamensis SAG 11.82, which fall into two distinct phylogenetic lineages. Herein, we suggest considering the C. amazonensis-cluster as the typical Cronbergia lineage. Meanwhile, the sequence originally adopted to describe the genus Cronbergia should be designated as a member of the genus Cylindrospermum. This study also emphasizes that both morphologic and genetic data must be generated with caution in order to avoid more misunderstandings in cyanobacterial systematics.

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.034
      Issue No: Vol. 29 (2017)
  • Increasing tetracycline concentrations on the performance and communities
           of mixed microalgae-bacteria photo-bioreactors
    • Authors: Yanghui Xiong; Dzenan Hozic; Ana L. Goncalves; Manuel Simões; Pei-Ying Hong
      Pages: 249 - 256
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Yanghui Xiong, Dzenan Hozic, Ana L. Goncalves, Manuel Simões, Pei-Ying Hong
      This study investigated the impact of varying concentrations of tetracycline on the performance of mixed microalgae-bacteria photo-bioreactors. Photo-bioreactors were assessed for their ability to remove carbon dioxide (CO2) from the biogas of anaerobic membrane bioreactor (anMBR), and nutrients from the anaerobic effluent. The varying concentrations of tetracycline had no impact on the removal of CO2 from biogas. 29% v/v of CO2 was completely removed to generate >20% v/v of oxygen (O2) in all reactors. Removal of nutrients and biomass was not affected at low concentrations of tetracycline (≤150μg/L), but 20mg/L of tetracycline lowered the biomass generation and removal efficiencies of phosphate. Conversely, high chlorophyll a and b content was observed at 20mg/L of tetracycline. High tetracycline level had no impact on the diversity of 18S rRNA gene-based microalgal communities but adversely affected the 16S rRNA gene-based microbial communities. Specifically, both Proteobacteria and Bacteroidetes phyla decreased in relative abundance but not phylum Chloroplast. Additionally, both nitrogen-fixing (e.g. Flavobacterium, unclassified Burkholderiales and unclassified Rhizobiaceae) and denitrifying groups (e.g. Hydrogenophaga spp.) were significantly reduced in relative abundance at high tetracycline concentration. Phosphate-accumulating microorganisms, Acinetobacter spp. and Pseudomonas spp. were similarly reduced upon exposure to high tetracycline concentration. Unclassified Comamonadaceae, however, increased in relative abundance, which correlated with an increase in the abundance of tetracycline resistance genes associated with efflux pump mechanism. Overall, the findings demonstrate that antibiotic concentrations in municipal wastewaters will not significantly affect the removal of nutrients by the mixed microalgae-bacteria photo-bioreactors. However, utilizing such photo-bioreactors as a polishing step for anMBRs that treat wastewaters with high tetracycline concentration may not be effective as evidenced from the lower nutrient removal and occurrence of antibiotic resistance genes.
      Graphical abstract image

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.033
      Issue No: Vol. 29 (2017)
  • Unraveling the lipid and pigment biosynthesis in Coelastrella sp. M-60:
           Genomics-enabled transcript profiling
    • Authors: Rathinasamy Karpagam; Kalimuthu Jawaharraj; Balasubramaniem Ashokkumar; Jayavel Sridhar; Perumal Varalakshmi
      Pages: 277 - 289
      Abstract: Publication date: January 2018
      Source:Algal Research, Volume 29
      Author(s): Rathinasamy Karpagam, Kalimuthu Jawaharraj, Balasubramaniem Ashokkumar, Jayavel Sridhar, Perumal Varalakshmi
      Microalgae can serve as a better feedstock for biodiesel leading to an alternate renewable energy resource, while algal strains which serve as a feedstock for biodiesel and bioactive pigments are scarce. Herein, we report the draft genome sequence and gene predictions of one such novel microalgal isolate Coelastrella sp. M-60 for the first time. The genome assembly is of ~80.2Mb size having 8163 predicted genes which revealed the presence of putative genes concerned with efficient nutrient uptake, bioremediation, in addition to lipid and carotenoid accumulation. Diverse unicellular algae of Chlorophyta, Rhodophyta and Phaeophyta have been reported for lipid and pigment biosynthesis and the predicted proteins of Coelastrella sp. M-60 showed substantial similarity with the aforementioned phyla. Differential expression analysis by real-time PCR regarding genes involved in the lipid and pigment biosynthetic pathways of Coelastrella sp. M-60 under osmotic stress conditions showed considerable upregulation in their transcript levels. The genome sequence availability of this potent microalga would enhance its utility through genetic manipulation strategies and help in deducing the mechanism of high value products accumulation in future.
      Graphical abstract image

      PubDate: 2017-12-19T18:07:20Z
      DOI: 10.1016/j.algal.2017.11.031
      Issue No: Vol. 29 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
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