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Publisher: Springer-Verlag   (Total: 2329 journals)

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Showing 1 - 200 of 2329 Journals sorted alphabetically
3D Research     Hybrid Journal   (Followers: 19, SJR: 0.214, h-index: 10)
4OR: A Quarterly J. of Operations Research     Hybrid Journal   (Followers: 9, SJR: 1.073, h-index: 25)
AAPS J.     Hybrid Journal   (Followers: 18, SJR: 1.192, h-index: 74)
AAPS PharmSciTech     Hybrid Journal   (Followers: 5, SJR: 0.718, h-index: 54)
Abdominal Imaging     Hybrid Journal   (Followers: 14, SJR: 0.723, h-index: 60)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 2, SJR: 0.447, h-index: 12)
Academic Psychiatry     Full-text available via subscription   (Followers: 22, SJR: 0.492, h-index: 32)
Academic Questions     Hybrid Journal   (Followers: 7, SJR: 0.135, h-index: 6)
Accreditation and Quality Assurance: J. for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26, SJR: 0.378, h-index: 30)
Acoustical Physics     Hybrid Journal   (Followers: 10, SJR: 0.355, h-index: 20)
Acoustics Australia     Hybrid Journal  
Acta Analytica     Hybrid Journal   (Followers: 7, SJR: 0.387, h-index: 6)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1, SJR: 0.624, h-index: 34)
Acta Biotheoretica     Hybrid Journal   (Followers: 5, SJR: 0.419, h-index: 25)
Acta Diabetologica     Hybrid Journal   (Followers: 14, SJR: 1.318, h-index: 46)
Acta Endoscopica     Hybrid Journal   (Followers: 1, SJR: 0.113, h-index: 8)
acta ethologica     Hybrid Journal   (Followers: 4, SJR: 0.465, h-index: 23)
Acta Geochimica     Hybrid Journal   (Followers: 3)
Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 1, SJR: 0.294, h-index: 13)
Acta Geotechnica     Hybrid Journal   (Followers: 6, SJR: 1.818, h-index: 22)
Acta Informatica     Hybrid Journal   (Followers: 5, SJR: 0.524, h-index: 32)
Acta Mathematica     Hybrid Journal   (Followers: 10, SJR: 8.021, h-index: 47)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2, SJR: 0.53, h-index: 29)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 5, SJR: 0.406, h-index: 30)
Acta Mathematica Vietnamica     Hybrid Journal   (SJR: 0.451, h-index: 5)
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal   (SJR: 0.22, h-index: 20)
Acta Mechanica     Hybrid Journal   (Followers: 18, SJR: 0.898, h-index: 52)
Acta Mechanica Sinica     Hybrid Journal   (Followers: 4, SJR: 0.426, h-index: 29)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5, SJR: 0.525, h-index: 18)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.524, h-index: 14)
Acta Neurochirurgica     Hybrid Journal   (Followers: 6, SJR: 0.833, h-index: 73)
Acta Neurologica Belgica     Hybrid Journal   (SJR: 0.348, h-index: 27)
Acta Neuropathologica     Hybrid Journal   (Followers: 3, SJR: 6.61, h-index: 117)
Acta Oceanologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 17)
Acta Parasitologica     Hybrid Journal   (Followers: 9, SJR: 0.581, h-index: 28)
Acta Physiologiae Plantarum     Hybrid Journal   (Followers: 2, SJR: 0.551, h-index: 39)
Acta Politica     Hybrid Journal   (Followers: 13, SJR: 0.658, h-index: 20)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5, SJR: 0.103, h-index: 4)
ADHD Attention Deficit and Hyperactivity Disorders     Hybrid Journal   (Followers: 20, SJR: 0.871, h-index: 15)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
Administration and Policy in Mental Health and Mental Health Services Research     Partially Free   (Followers: 14, SJR: 0.795, h-index: 40)
Adsorption     Hybrid Journal   (Followers: 4, SJR: 0.774, h-index: 52)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 3, SJR: 0.319, h-index: 15)
Advances in Atmospheric Sciences     Hybrid Journal   (Followers: 34, SJR: 0.959, h-index: 44)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15, SJR: 1.255, h-index: 44)
Advances in Contraception     Hybrid Journal   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 53, SJR: 1.113, h-index: 14)
Advances in Gerontology     Partially Free   (Followers: 8, SJR: 0.141, h-index: 3)
Advances in Health Sciences Education     Hybrid Journal   (Followers: 23, SJR: 1.397, h-index: 42)
Advances in Manufacturing     Hybrid Journal   (Followers: 3, SJR: 0.2, h-index: 4)
Advances in Polymer Science     Hybrid Journal   (Followers: 40, SJR: 0.637, h-index: 89)
Advances in Therapy     Hybrid Journal   (Followers: 5, SJR: 0.79, h-index: 44)
Aegean Review of the Law of the Sea and Maritime Law     Hybrid Journal   (Followers: 7)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2, SJR: 0.882, h-index: 23)
Aerobiologia     Hybrid Journal   (Followers: 1, SJR: 0.511, h-index: 36)
Aesthetic Plastic Surgery     Hybrid Journal   (Followers: 8, SJR: 0.821, h-index: 49)
African Archaeological Review     Hybrid Journal   (Followers: 14, SJR: 0.612, h-index: 24)
Afrika Matematika     Hybrid Journal   (Followers: 1, SJR: 0.248, h-index: 6)
AGE     Hybrid Journal   (Followers: 7, SJR: 1.358, h-index: 33)
Ageing Intl.     Hybrid Journal   (Followers: 7, SJR: 0.337, h-index: 10)
Aggiornamenti CIO     Hybrid Journal   (Followers: 1)
Aging Clinical and Experimental Research     Hybrid Journal   (Followers: 3, SJR: 0.529, h-index: 55)
Agricultural Research     Hybrid Journal   (Followers: 3)
Agriculture and Human Values     Hybrid Journal   (Followers: 12, SJR: 1.197, h-index: 49)
Agroforestry Systems     Hybrid Journal   (Followers: 20, SJR: 0.64, h-index: 56)
Agronomy for Sustainable Development     Hybrid Journal   (Followers: 10, SJR: 1.732, h-index: 59)
AI & Society     Hybrid Journal   (Followers: 7, SJR: 0.171, h-index: 19)
AIDS and Behavior     Hybrid Journal   (Followers: 13, SJR: 2.006, h-index: 71)
Air Quality, Atmosphere & Health     Hybrid Journal   (Followers: 3, SJR: 0.706, h-index: 19)
Akupunktur & Aurikulomedizin     Full-text available via subscription   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 2, SJR: 0.566, h-index: 18)
Algebra Universalis     Hybrid Journal   (Followers: 2, SJR: 0.388, h-index: 22)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1, SJR: 0.868, h-index: 20)
Algorithmica     Hybrid Journal   (Followers: 7, SJR: 0.898, h-index: 56)
Allergo J.     Full-text available via subscription   (Followers: 1, SJR: 0.183, h-index: 20)
Allergo J. Intl.     Hybrid Journal   (Followers: 2)
Alpine Botany     Hybrid Journal   (Followers: 4, SJR: 0.729, h-index: 20)
ALTEX : Alternatives to Animal Experimentation     Open Access   (Followers: 3, SJR: 1.392, h-index: 32)
AMBIO     Hybrid Journal   (Followers: 14, SJR: 1.094, h-index: 87)
American J. of Cardiovascular Drugs     Hybrid Journal   (Followers: 10, SJR: 0.864, h-index: 39)
American J. of Community Psychology     Hybrid Journal   (Followers: 24, SJR: 1.237, h-index: 83)
American J. of Criminal Justice     Hybrid Journal   (Followers: 7, SJR: 0.634, h-index: 13)
American J. of Cultural Sociology     Hybrid Journal   (Followers: 11, SJR: 0.283, h-index: 3)
American J. of Dance Therapy     Hybrid Journal   (Followers: 4, SJR: 0.175, h-index: 13)
American J. of Potato Research     Hybrid Journal   (Followers: 2, SJR: 0.558, h-index: 35)
American J. of Psychoanalysis     Hybrid Journal   (Followers: 21, SJR: 0.293, h-index: 13)
American Sociologist     Hybrid Journal   (Followers: 11, SJR: 0.18, h-index: 13)
Amino Acids     Hybrid Journal   (Followers: 7, SJR: 1.362, h-index: 83)
AMS Review     Partially Free   (Followers: 4)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 5, SJR: 0.21, h-index: 37)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 4, SJR: 0.665, h-index: 7)
Analysis in Theory and Applications     Hybrid Journal  
Analysis of Verbal Behavior     Hybrid Journal   (Followers: 4)
Analytical and Bioanalytical Chemistry     Hybrid Journal   (Followers: 28, SJR: 1.096, h-index: 123)
Anatomical Science Intl.     Hybrid Journal   (Followers: 2, SJR: 0.301, h-index: 26)
Angewandte Schmerztherapie und Palliativmedizin     Hybrid Journal  
Angiogenesis     Hybrid Journal   (Followers: 3, SJR: 2.212, h-index: 69)
Animal Cognition     Hybrid Journal   (Followers: 15, SJR: 1.122, h-index: 55)
Annales françaises de médecine d'urgence     Hybrid Journal   (Followers: 1, SJR: 0.156, h-index: 4)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3, SJR: 1.377, h-index: 32)
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4)
Annali dell'Universita di Ferrara     Hybrid Journal   (SJR: 0.504, h-index: 14)
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1, SJR: 1.167, h-index: 26)
Annals of Behavioral Medicine     Hybrid Journal   (Followers: 12, SJR: 2.112, h-index: 98)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18, SJR: 1.182, h-index: 94)
Annals of Combinatorics     Hybrid Journal   (Followers: 3, SJR: 0.849, h-index: 15)
Annals of Data Science     Hybrid Journal   (Followers: 8)
Annals of Dyslexia     Hybrid Journal   (Followers: 9, SJR: 0.857, h-index: 40)
Annals of Finance     Hybrid Journal   (Followers: 28, SJR: 0.686, h-index: 14)
Annals of Forest Science     Hybrid Journal   (Followers: 4, SJR: 0.929, h-index: 57)
Annals of Global Analysis and Geometry     Hybrid Journal   (Followers: 1, SJR: 1.136, h-index: 23)
Annals of Hematology     Hybrid Journal   (Followers: 13, SJR: 1.117, h-index: 62)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6, SJR: 0.593, h-index: 42)
Annals of Microbiology     Hybrid Journal   (Followers: 9, SJR: 0.402, h-index: 26)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 5, SJR: 0.68, h-index: 45)
Annals of Operations Research     Hybrid Journal   (Followers: 8, SJR: 1.186, h-index: 78)
Annals of Regional Science     Hybrid Journal   (Followers: 7, SJR: 0.405, h-index: 42)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annals of Solid and Structural Mechanics     Hybrid Journal   (Followers: 10, SJR: 0.553, h-index: 8)
Annals of Surgical Oncology     Hybrid Journal   (Followers: 11, SJR: 1.902, h-index: 127)
Annals of Telecommunications     Hybrid Journal   (Followers: 7, SJR: 0.315, h-index: 25)
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1, SJR: 0.931, h-index: 31)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5, SJR: 0.992, h-index: 87)
Apidologie     Hybrid Journal   (Followers: 4, SJR: 1.14, h-index: 57)
APOPTOSIS     Hybrid Journal   (Followers: 8, SJR: 1.554, h-index: 87)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2, SJR: 0.354, h-index: 27)
Applications of Mathematics     Hybrid Journal   (Followers: 1, SJR: 0.274, h-index: 20)
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 44, SJR: 0.575, h-index: 80)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 17, SJR: 0.267, h-index: 26)
Applied Categorical Structures     Hybrid Journal   (Followers: 2, SJR: 0.361, h-index: 21)
Applied Composite Materials     Hybrid Journal   (Followers: 46, SJR: 0.705, h-index: 35)
Applied Entomology and Zoology     Partially Free   (Followers: 2, SJR: 0.554, h-index: 34)
Applied Geomatics     Hybrid Journal   (Followers: 3, SJR: 0.323, h-index: 9)
Applied Geophysics     Hybrid Journal   (Followers: 7, SJR: 0.541, h-index: 13)
Applied Intelligence     Hybrid Journal   (Followers: 14, SJR: 0.777, h-index: 43)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3, SJR: 0.358, h-index: 34)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 4, SJR: 0.955, h-index: 33)
Applied Mathematics - A J. of Chinese Universities     Hybrid Journal   (SJR: 0.275, h-index: 8)
Applied Mathematics and Mechanics     Hybrid Journal   (Followers: 4, SJR: 0.37, h-index: 26)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 61, SJR: 1.262, h-index: 161)
Applied Physics A     Hybrid Journal   (Followers: 7, SJR: 0.535, h-index: 121)
Applied Physics B: Lasers and Optics     Hybrid Journal   (Followers: 23, SJR: 0.983, h-index: 104)
Applied Psychophysiology and Biofeedback     Hybrid Journal   (Followers: 7, SJR: 0.677, h-index: 47)
Applied Research in Quality of Life     Hybrid Journal   (Followers: 10, SJR: 0.288, h-index: 15)
Applied Solar Energy     Hybrid Journal   (Followers: 15, SJR: 0.251, h-index: 6)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4, SJR: 0.351, h-index: 9)
Aquaculture Intl.     Hybrid Journal   (Followers: 22, SJR: 0.613, h-index: 40)
Aquarium Sciences and Conservation     Hybrid Journal   (Followers: 1)
Aquatic Ecology     Hybrid Journal   (Followers: 30, SJR: 0.646, h-index: 44)
Aquatic Geochemistry     Hybrid Journal   (Followers: 3, SJR: 0.764, h-index: 39)
Aquatic Sciences     Hybrid Journal   (Followers: 12, SJR: 1.172, h-index: 53)
Arabian J. for Science and Engineering     Hybrid Journal   (Followers: 5, SJR: 0.345, h-index: 20)
Arabian J. of Geosciences     Hybrid Journal   (Followers: 1, SJR: 0.417, h-index: 16)
Archaeological and Anthropological Sciences     Hybrid Journal   (Followers: 21, SJR: 1.056, h-index: 15)
Archaeologies     Hybrid Journal   (Followers: 12, SJR: 0.397, h-index: 13)
Archiv der Mathematik     Hybrid Journal   (Followers: 1, SJR: 0.597, h-index: 29)
Archival Science     Hybrid Journal   (Followers: 52, SJR: 0.804, h-index: 22)
Archive for History of Exact Sciences     Hybrid Journal   (Followers: 7, SJR: 0.28, h-index: 15)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 1, SJR: 0.946, h-index: 23)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (SJR: 4.091, h-index: 66)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4, SJR: 0.865, h-index: 40)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4, SJR: 2.841, h-index: 40)
Archives of Dermatological Research     Hybrid Journal   (Followers: 6, SJR: 0.9, h-index: 65)
Archives of Environmental Contamination and Toxicology     Hybrid Journal   (Followers: 10, SJR: 0.846, h-index: 84)
Archives of Gynecology and Obstetrics     Hybrid Journal   (Followers: 16, SJR: 0.695, h-index: 47)
Archives of Microbiology     Hybrid Journal   (Followers: 8, SJR: 0.702, h-index: 85)
Archives of Orthopaedic and Trauma Surgery     Hybrid Journal   (Followers: 8, SJR: 1.039, h-index: 56)
Archives of Osteoporosis     Hybrid Journal   (Followers: 2, SJR: 1.092, h-index: 13)
Archives of Sexual Behavior     Hybrid Journal   (Followers: 9, SJR: 1.198, h-index: 74)
Archives of Toxicology     Hybrid Journal   (Followers: 16, SJR: 1.595, h-index: 76)
Archives of Virology     Hybrid Journal   (Followers: 5, SJR: 1.086, h-index: 90)
Archives of Women's Mental Health     Hybrid Journal   (Followers: 13, SJR: 1.264, h-index: 50)
Archivio di Ortopedia e Reumatologia     Hybrid Journal  
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2, SJR: 1.2, h-index: 42)
ArgoSpine News & J.     Hybrid Journal   (SJR: 0.102, h-index: 3)
Argumentation     Hybrid Journal   (Followers: 5, SJR: 0.295, h-index: 18)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arkiv för Matematik     Hybrid Journal   (Followers: 1, SJR: 0.948, h-index: 22)
Arnold Mathematical J.     Hybrid Journal   (Followers: 1)
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 1, SJR: 0.797, h-index: 17)
Arthroskopie     Hybrid Journal   (Followers: 1, SJR: 0.145, h-index: 8)
Artificial Intelligence and Law     Hybrid Journal   (Followers: 10, SJR: 0.288, h-index: 25)
Artificial Intelligence Review     Hybrid Journal   (Followers: 15, SJR: 0.948, h-index: 48)
Artificial Life and Robotics     Hybrid Journal   (Followers: 8, SJR: 0.231, h-index: 14)
Asia Europe J.     Hybrid Journal   (Followers: 4, SJR: 0.247, h-index: 9)
Asia Pacific Education Review     Hybrid Journal   (Followers: 9, SJR: 0.371, h-index: 17)
Asia Pacific J. of Management     Hybrid Journal   (Followers: 11, SJR: 1.676, h-index: 50)
Asia-Pacific Education Researcher     Hybrid Journal   (Followers: 11, SJR: 0.353, h-index: 13)
Asia-Pacific Financial Markets     Hybrid Journal   (Followers: 2, SJR: 0.19, h-index: 15)
Asia-Pacific J. of Atmospheric Sciences     Hybrid Journal   (Followers: 20, SJR: 1.006, h-index: 14)
Asian Business & Management     Hybrid Journal   (Followers: 7, SJR: 0.41, h-index: 10)
Asian J. of Business Ethics     Hybrid Journal   (Followers: 7)
Asian J. of Criminology     Hybrid Journal   (Followers: 5, SJR: 0.263, h-index: 8)
AStA Advances in Statistical Analysis     Hybrid Journal   (Followers: 2, SJR: 0.681, h-index: 15)
AStA Wirtschafts- und Sozialstatistisches Archiv     Hybrid Journal   (Followers: 5, SJR: 0.195, h-index: 5)
ästhetische dermatologie & kosmetologie     Full-text available via subscription  
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 21, SJR: 4.511, h-index: 44)
Astronomy Letters     Hybrid Journal   (Followers: 19, SJR: 0.58, h-index: 30)
Astronomy Reports     Hybrid Journal   (Followers: 12, SJR: 0.473, h-index: 23)
Astrophysical Bulletin     Hybrid Journal   (Followers: 2, SJR: 0.469, h-index: 11)

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Journal Cover Applied Microbiology and Biotechnology
  [SJR: 1.262]   [H-I: 161]   [61 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1432-0614 - ISSN (Online) 0175-7598
   Published by Springer-Verlag Homepage  [2329 journals]
  • Occurrence and function of enzymes for lignocellulose degradation in
           commercial Agaricus bisporus cultivation
    • Authors: Mirjam A. Kabel; Edita Jurak; Miia R. Mäkelä; Ronald P. de Vries
      Pages: 4363 - 4369
      Abstract: The white button mushroom Agaricus bisporus is economically the most important commercially produced edible fungus. It is grown on carbon- and nitrogen-rich substrates, such as composted cereal straw and animal manure. The commercial mushroom production process is usually performed in buildings or tunnels under highly controlled environmental conditions. In nature, the basidiomycete A. bisporus has a significant impact on the carbon cycle in terrestrial ecosystems as a saprotrophic decayer of leaf litter. In this mini-review, the fate of the compost plant cell wall structures, xylan, cellulose and lignin, is discussed. A comparison is made from the structural changes observed to the occurrence and function of enzymes for lignocellulose degradation present, with a special focus on the extracellular enzymes produced by A. bisporus. In addition, recent advancements in whole genome level molecular studies in various growth stages of A. bisporus in compost are reviewed.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8294-5
      Issue No: Vol. 101, No. 11 (2017)
       
  • Metabolic perturbation to enhance polyketide and nonribosomal peptide
           antibiotic production using triclosan and ribosome-targeting drugs
    • Authors: Yukinori Tanaka; Masumi Izawa; Yoshikazu Hiraga; Yuya Misaki; Tomoko Watanabe; Kozo Ochi
      Pages: 4417 - 4431
      Abstract: Although transcriptional activation of pathwayspecific positive regulatory genes and/or biosynthetic genes is primarily important for enhancing secondary metabolite production, reinforcement of substrate supply, as represented by primary metabolites, is also effective. For example, partial inhibition of fatty acid synthesis with ARC2 (an analog of triclosan) was found to enhance polyketide antibiotic production. Here, we demonstrate that this approach is effective even for industrial high-producing strains, for example enhancing salinomycin production by 40%, reaching 30.4 g/l of salinomycin in an industrial Streptomyces albus strain. We also hypothesized that a similar approach would be applicable to another important antibiotic group, nonribosomal peptide (NRP) antibiotics. We therefore attempted to partially inhibit protein synthesis by using ribosome-targeting drugs at subinhibitory concentrations (1/50∼1/2 of MICs), which may result in the preferential recruitment of intracellular amino acids to the biosynthesis of NRP antibiotics rather than to protein synthesis. Among the ribosome-targeting drugs examined, chloramphenicol at subinhibitory concentrations was most effective at enhancing the production by Streptomyces of NRP antibiotics such as actinomycin, calcium-dependent antibiotic (CDA), and piperidamycin, often resulting in an almost 2-fold increase in antibiotic production. Chloramphenicol activated biosynthetic genes at the transcriptional level and increased amino acid pool sizes 1.5- to 6-fold, enhancing the production of actinomycin and CDA. This “metabolic perturbation” approach using subinhibitory concentrations of ribosome-targeting drugs is a rational method of enhancing NRP antibiotic production, being especially effective in transcriptionally activated (e.g., rpoB mutant) strains. Because this approach does not require prior genetic information, it may be widely applicable for enhancing bacterial production of NRP antibiotics and bioactive peptides.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8216-6
      Issue No: Vol. 101, No. 11 (2017)
       
  • Lateral flow assay for rapid detection of white spot syndrome virus (WSSV)
           using a phage-displayed peptide as bio-recognition probe
    • Authors: Prabir Kumar Kulabhusan; Jyutika M. Rajwade; A. S. Sahul Hameed; Kishore M. Paknikar
      Pages: 4459 - 4469
      Abstract: White spot disease caused by the white spot syndrome virus (WSSV) has a major socio-economic impact on shrimp farming in India. It has been realized that a field-usable diagnostic capable of rapid detection of WSSV can prevent huge economic losses in disease outbreaks. In this work, we explored the possibility of using a peptide as bio-recognition probe in a field-usable device for the detection of WSSV from infected shrimps and prawns. A commercially available random phage-display library was screened against rVP28 (a major structural protein of WSSV, expressed as a recombinant protein in Escherichia coli). A bacteriophage clone VP28-4L was obtained, and its binding to purified rVP28 protein as well as WSSV from infected shrimp Litopaeneus vannamei tissue was confirmed by ELISA and western blot. The apparent equilibrium dissociation constant (Kd,app) was calculated to be 810 nM. VP28-4L did not show cross-reactivity with any other shrimp viruses. A 12-mer peptide (pep28, with the sequence ′TFQAFDLSPFPS′) displayed on the VP28-4L was synthesized, and its diagnostic potential was evaluated in a lateral flow assay (LFA). Visual detection of WSSV could be achieved using biotinylated-pep28 and streptavidin-conjugated gold nanoparticles. In LFA, 12.5 μg/mL of the virus could be detected from L. vannamei gill tissue homogenate within 20 min. Pep28 thus becomes an attractive candidate in bio-recognition of WSSV in field-usable diagnostic platforms benefitting the aquaculture sector.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8232-6
      Issue No: Vol. 101, No. 11 (2017)
       
  • YLL056C from Saccharomyces cerevisiae encodes a novel protein with
           aldehyde reductase activity
    • Authors: Han-Yu Wang; Di-Fan Xiao; Chang Zhou; Lin-Lu Wang; Lan Wu; Ya-Ting Lu; Quan-Ju Xiang; Ke Zhao; Xi Li; Meng -Gen Ma
      Pages: 4507 - 4520
      Abstract: The short-chain dehydrogenase/reductase (SDR) family, the largest family in dehydrogenase/reductase superfamily, is divided into “classical,” “extended,” “intermediate,” “divergent,” “complex,” and “atypical” groups. Recently, several open reading frames (ORFs) were characterized as intermediate SDR aldehyde reductase genes in Saccharomyces cerevisiae. However, no functional protein in the atypical group has been characterized in S. cerevisiae till now. Herein, we report that an uncharacterized ORF YLL056C from S. cerevisiae was significantly upregulated under high furfural (2-furaldehyde) or 5-(hydroxymethyl)-2-furaldehyde concentrations, and transcription factors Yap1p, Hsf1p, Pdr1/3p, Yrr1p, and Stb5p likely controlled its upregulated transcription. This ORF indeed encoded a protein (Yll056cp), which was grouped into the atypical subgroup 7 in the SDR family and localized to the cytoplasm. Enzyme activity assays showed that Yll056cp is not a quinone or ketone reductase but an NADH-dependent aldehyde reductase, which can reduce at least seven aldehyde compounds. This enzyme showed the best Vmax, Kcat, and Kcat/Km to glycolaldehyde, but the highest affinity (Km) to formaldehyde. The optimum pH and temperature of this enzyme was pH 6.5 for reduction of glycolaldehyde, furfural, formaldehyde, butyraldehyde, and propylaldehyde, and 30 °C for reduction of formaldehyde or 35 °C for reduction of glycolaldehyde, furfural, butyraldehyde, and propylaldehyde. Temperature and pH affected stability of this enzyme and this influence varied with aldehyde substrate. Metal ions, salts, and chemical protective additives, especially at high concentrations, had different influence on enzyme activities for reduction of different aldehydes. This research provided guidelines for study of more uncharacterized atypical SDR enzymes from S. cerevisiae and other organisms.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8209-5
      Issue No: Vol. 101, No. 11 (2017)
       
  • General assay for enzymes in the heptose biosynthesis pathways using
           electrospray ionization mass spectrometry
    • Authors: Jimin Park; Daeun Lee; Eun Kyoung Seo; Jae-Sang Ryu; Dong Hae Shin
      Pages: 4521 - 4532
      Abstract: The ADP-l-glycero-β-d-manno-heptose and the GDP-6-deoxy-α-d-manno-heptose biosynthesis pathways play important roles in constructing lipopolysaccharide of Gram-negative bacteria. Blocking the pathways is lethal or increases antibiotic susceptibility to pathogens. Therefore, the enzymes involved in the pathways are novel antibiotic drug targets. Here, we designed an efficient method to assay the whole enzymes in the pathways using mass spectrometry and screened 148 compounds. One promising lead is (−)-nyasol targeting d-glycero-α-d-manno-heptose-1-phosphate guanylyltransferase (HddC) included in the GDP-6-deoxy-α-d-manno-heptose biosynthesis pathway from Burkholderia pseudomallei. The inhibitory activity of the lead compound against HddC has been confirmed by blocking the system transferring the guanosine monophosphate (GMP) moiety to α-d-glucose-1-phosphate. (−)-Nyasol exhibits the half maximal inhibitory concentration (IC50) value of 17.6 μM. A further study is going on using (−)-nyasol derivatives to find better leads with high affinity.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8148-1
      Issue No: Vol. 101, No. 11 (2017)
       
  • Understanding the mechanisms of zinc bacitracin and avilamycin on animal
           production: linking gut microbiota and growth performance in chickens
    • Authors: Eduardo Crisol-Martínez; Dragana Stanley; Mark S. Geier; Robert J. Hughes; Robert J. Moore
      Pages: 4547 - 4559
      Abstract: Unravelling the mechanisms of how antibiotics influence growth performance through changes in gut microbiota can lead to the identification of highly productive microbiota in animal production. Here we investigated the effect of zinc bacitracin and avilamycin on growth performance and caecal microbiota in chickens and analysed associations between individual bacteria and growth performance. Two trials were undertaken; each used 96 individually caged 15-day-old Cobb broilers. Trial 1 had a control group (n = 48) and a zinc bacitracin (50 ppm) treatment group (n = 48). Trial 2 had a control group (n = 48) and an avilamycin (15 ppm) treatment group (n = 48). Chicken growth performance was evaluated over a 10-day period, and caecal microbiota was characterised by sequencing of bacterial 16S rRNA gene amplicons. Avilamycin produced no effect on growth performance and exhibited little significant disturbance of the microbiota structure. However, zinc bacitracin reduced the feed conversion ratio (FCR) in treated birds, changed the composition and increased the diversity of their caecal microbiota by reducing dominant species. Avilamycin only produced minor reductions in the abundance of two microbial taxa, whereas zinc bacitracin produced relatively large shifts in a number of taxa, primarily Lactobacillus species. Also, a number of phylotypes closely related to lactobacilli species were positively or negatively correlated with FCR values, suggesting contrasting effects of Lactobacillus spp. on chicken growth performance. By harnessing such bacteria, it may be possible to develop high-productivity strategies in poultry that rely on the use of probiotics and less on in-feed antibiotics.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8193-9
      Issue No: Vol. 101, No. 11 (2017)
       
  • RT-qPCR with chimeric dU stem-loop primer is efficient for the detection
           of bacterial small RNAs
    • Authors: Yangfan Wu; Xuejiao Xing; Ting You; Rubing Liang; Jianhua Liu
      Pages: 4561 - 4568
      Abstract: Small non-coding RNAs are considered be involved in the regulation of multiple cellular processes. Quantitative reverse transcription PCR (RT-qPCR) is widely used in the detection of eukaryotic microRNA, and the stem-loop primers can improve the specificity and efficiency of reverse transcription. However, the loop structure of primers probably influence the next quantitative amplification due to the base stacking and steric hindrance. Here, we designed a chimeric stem-loop primer with a deoxyuracil (dU) base located near the RNA matching part. After the reverse transcription, uracil-DNA glycosylase (UDG) treatment was used to remove the dU base and destroy the stem-loop structure of RT product. Enzymatic assay confirmed that the recombinant UDG could efficiently eliminate the dU base in the oligonucleotide. Transcriptions of two small RNAs (TFF and ryeA) in Escherichia coli were detected by RT-qPCR with different primers. Results showed that the use of the chimeric dU stem-loop primer and UDG treatment could enhance the detection specificity and sensitivity about 1.1- to 3.4-fold, compared to those with traditional stem-loop primer and linear primer. Total RNA of 1–10 pg was enough for efficient detection with the chimeric stem-loop primers. In a word, this strategy could promote the RT-qPCR detection efficiency on the transcription of bacterial small RNAs even in trace samples and can facilitate the detection of exiguous change in cellular metabolism.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8181-0
      Issue No: Vol. 101, No. 11 (2017)
       
  • Rapid customised operon assembly by yeast recombinational cloning
    • Authors: Michael A. Liu; Johanna J. Kenyon; Jason Lee; Peter R. Reeves
      Pages: 4569 - 4580
      Abstract: We have developed a system called the Operon Assembly Protocol (OAP), which takes advantage of the homologous recombination DNA repair pathway in Saccharomyces cerevisiae to assemble full-length operons from a series of overlapping PCR products into a specially engineered yeast-Escherichia coli shuttle vector. This flexible, streamlined system can be used to assemble several operon clones simultaneously, and each clone can be expressed in the same E. coli tester strain to facilitate direct functional comparisons. We demonstrated the utility of the OAP by assembling and expressing a series of E. coli O1A O-antigen gene cluster clones containing various gene deletions or replacements. We then used these constructs to assess the substrate preferences of several Wzx flippases, which are responsible for translocation of oligosaccharide repeat units (O units) across the inner membrane during O-antigen biosynthesis. We were able to identify several O unit structural features that appear to be important determinants of Wzx substrate preference. The OAP system should be broadly applicable for the genetic manipulation of any bacterial operon and can be modified for use in other host species. It could also have potential uses in fields such as glycoengineering.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8213-9
      Issue No: Vol. 101, No. 11 (2017)
       
  • Engineering of the LysR family transcriptional regulator FkbR1 and its
           target gene to improve ascomycin production
    • Authors: Kejing Song; Liang Wei; Jiao Liu; Junhua Wang; Haishan Qi; Jianping Wen
      Pages: 4581 - 4592
      Abstract: Ascomycin (FK520), a macrocyclic polyketide natural antibiotic, displays high anti-fungal and immunosuppressive activity. In this study, the LysR family transcriptional regulator FkbR1 was characterized, and its role in ascomycin biosynthesis was explored by gene deletion, complementation, and overexpression. Inactivation of fkbR1 led to 67.5% reduction of ascomycin production, which was restored by complementation of fkbR1. Overexpression of fkbR1 resulted in a 33.5% increase in ascomycin production compared with the parent strain FS35. These findings indicated that FkbR1 was a positive regulator for ascomycin production. Quantitative RT-PCR analysis revealed that the expressions of fkbE, fkbF, fkbS, and fkbU were downregulated in the fkbR1 deletion strain and upregulated in the fkbR1 overexpression strain. Electrophoretic mobility shift assays (EMSAs) in vitro and chromatin immunoprecipitation (ChIP)-qPCR assays in vivo indicated that FkbR1 bound to the intergenic region of fkbR1-fkbE. To investigate the roles of the target genes fkbE and fkbF in ascomycin production, the deletion and overexpressions of fkbE and fkbF were implemented, respectively. Overexpression of fkbE resulted in a 45.6% increase in ascomycin production, but little change was observed in fkbF overexpression strain. To further enhance ascomycin production, the fkbR1 and fkbE combinatorial overexpression strain OfkbRE was constructed with the ascomycin yield increased by 69.9% to 536.7 mg/L compared with that of the parent strain. Our research provided a helpful strategy to increase ascomycin production via engineering FkbR1 and its target gene.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8242-4
      Issue No: Vol. 101, No. 11 (2017)
       
  • DASH-type cryptochromes regulate fruiting body development and secondary
           metabolism differently than CmWC-1 in the fungus Cordyceps militaris
    • Authors: Fen Wang; Xinhua Song; Xiaoming Dong; Jiaojiao Zhang; Caihong Dong
      Pages: 4645 - 4657
      Abstract: Cryptochromes (CRYs) belong to the photolyase/cryptochrome flavoprotein family, which is widely distributed in all kingdoms. A phylogenetic analysis indicated that three Cordyceps militaris proteins [i.e., cryptochrome DASH (CmCRY-DASH), (6-4) photolyase, and cyclobutane pyrimidine dimer (CPD) class I photolyase] belong to separate fungal photolyase/cryptochrome subfamilies. CmCRY-DASH consists of DNA photolyase and flavin adenine dinucleotide-binding domains, with RGG repeats in a C-terminal extension. Considerably, more carotenoids and cordycepin accumulated in the ΔCmcry-DASH strain than in the wild-type or ΔCmwc-1 strains, indicating an inhibitory role for CmCRY-DASH in these biosynthetic pathways. Fruiting body primordia could form in the ΔCmcry-DASH strain, but the fruiting bodies were unable to elongate normally, differently from the Cmwc-1 disruption strain, where primordium differentiation did not occur. Cmcry-DASH expression is induced by light in the wild-type strain, but not in the ΔCmwc-1 strain. CmCRY-DASH is also necessary for the expression of Cmwc-1, implying that Cmcry-DASH and Cmwc-1 exhibit interdependent expression. The Cmvvd expression levels in the wild-type and ΔCmcry-DASH strains increased considerably following irradiation, while Cmvvd expression in the ΔCmwc-1 strain was not induced by light. It is speculated that the photo adaptation may be faster in the Cmcry-DASH mutant based on Cmvvd transcript dynamics. These results provide new insights into the biological functions of fungal DASH CRYs. Furthermore, the DASH CRYs may regulate fruiting body development and secondary metabolism differently than WC-1.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8276-7
      Issue No: Vol. 101, No. 11 (2017)
       
  • Effect of methyl-β-cyclodextrin on gene expression in microbial
           conversion of phytosterol
    • Authors: Victoria Y. Shtratnikova; Mikhail I. Schelkunov; Dmitry V. Dovbnya; Eugeny Y. Bragin; Marina V. Donova
      Pages: 4659 - 4667
      Abstract: Modified β-cyclodextrins are widely used for the enhancement of microbial conversions of lipophilic compounds such as steroids. Multiple mechanisms of cyclodextrin-mediated enhancement of phytosterol bioconversion by mycobacteria had previously been shown to include steroid solubilization, alterations in the cell wall permeability for both steroids and nutrients, facilitation of protein leaking, and activity suppression of some steroid-transforming enzymes.In this work, we studied whether cyclodextrins might affect expression of the genes involved in the steroid catabolic pathway. Phytosterol bioconversion with 9α-hydroxy-androst-4-ene-3,17-dione accumulation by Mycobacterium sp. VKM Ac-1817D in the presence of methylated β-cyclodextrin (MCD) was investigated. RNA sequencing of the whole transcriptomes in different combinations of phytosterol and MCD showed a similar expression level of the steroid catabolism genes related to the KstR-regulon and was responsible for side chain and initial steps of steroid core oxidation; whereas, induction levels of the genes related to the KstR2-regulon were attenuated in the presence of MCD in this strain. The data were attenuated with quantitative real-time PCR.The results contribute to the understanding of cyclodextrin effects on microbial steroid conversion and provide a basis for the use of cyclodextrins as expression enhancers for studies of sterol catabolism in actinobacteria.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8288-3
      Issue No: Vol. 101, No. 11 (2017)
       
  • The susceptibility of Staphylococcus aureus CIP 65.8 and Pseudomonas
           aeruginosa ATCC 9721 cells to the bactericidal action of nanostructured
           Calopteryx haemorrhoidalis damselfly wing surfaces
    • Authors: Vi Khanh Truong; Nipuni Mahanamanam Geeganagamage; Vladimir A. Baulin; Jitraporn Vongsvivut; Mark J. Tobin; Pere Luque; Russell J. Crawford; Elena P. Ivanova
      Pages: 4683 - 4690
      Abstract: Nanostructured insect wing surfaces have been reported to possess the ability to resist bacterial colonization through the mechanical rupture of bacterial cells coming into contact with the surface. In this work, the susceptibility of physiologically young, mature and old Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9721 bacterial cells, to the action of the bactericidal nano-pattern of damselfly Calopteryx haemorrhoidalis wing surfaces, was investigated. The results were obtained using several surface characterization techniques including optical profilometry, scanning electron microscopy, synchrotron-sourced Fourier transform infrared microspectroscopy, water contact angle measurements and antibacterial assays. The data indicated that the attachment propensity of physiologically young S. aureus CIP 65.8T and mature P. aeruginosa ATCC 9721 bacterial cells was greater than that of the cells at other stages of growth. Both the S. aureus CIP 65.8T and P. aeruginosa ATCC 9721 cells, grown at the early (1 h) and late stationary phase (24 h), were found to be most susceptible to the action of the wings, with up to 89.7 and 61.3% as well as 97.9 and 97.1% dead cells resulting from contact with the wing surface, respectively.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8205-9
      Issue No: Vol. 101, No. 11 (2017)
       
  • Rapid killing of bacteria by a new type of photosensitizer
    • Authors: Yaxin Zhang; Ke Zheng; Zhuo Chen; Jincan Chen; Ping Hu; Linrong Cai; Zafar Iqbal; Mingdong Huang
      Pages: 4691 - 4700
      Abstract: Photodynamic antimicrobial chemotherapy (PACT) uses non-traditional mechanisms (free radicals) and is a highly advocated method with promise of inactivating drug-resistance bacteria for local infections. However, there is no related drug used in clinical practice yet. Therefore, new photosensitizers for PACT are under active development. Here, we report the synthesis of a series of photosensitizers with variable positive charges (ZnPc(TAP)4 n+, n = 0, 4, 8, 12) and their inactivation against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The binding kinetics of ZnPc(TAP)4 n+ to bacteria were measured by flow cytometer. Reactive oxygen species (ROS) generation mechanism of the photosensitizers was studied. The toxicity of these compounds to human blood cells was also evaluated. These compounds showed negligible toxicity against human erythocytes but potent bactericidal effects. The compound with 8 positive charges, ZnPc(TAP)4 8+, turned out to have the strongest antibacterial effect among this series of compounds, giving IC50 value of 59 nM at a light dosage of 5 J/cm2 toward E. coli. For a multi-resistant E. coli strain, ZnPc(TAP)4 8+ decreased the bacteria load by 1000-fold at a concentration of 1 μM. Interestingly, ZnPc(TAP)4 12+, instead of ZnPc(TAP)4 8+, exhibited the highest amount of binding to bacteria. Flow cytometry studies showed that all PSs have fast binding onto bacteria, reaching saturated binding within 5 min. Mechanistically, ZnPc(TAP)4 12+ generated ROS primarily via Type I mechanism, while ZnPc(TAP)4 4+ or ZnPc(TAP)4 8+ created ROS by both type I and type II mechanisms. ZnPc(TAP)4 n+ are highly potent, rapid-acting and non-toxic photosensitizers capable of inactivating bacteria.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8133-8
      Issue No: Vol. 101, No. 11 (2017)
       
  • Identification of the orsellinic acid synthase PKS63787 for the
           biosynthesis of antroquinonols in Antrodia cinnamomea
    • Authors: Po-Wei Yu; Ting-Yu Cho; Ruey-Fen Liou; Shean-Shong Tzean; Tzong-Huei Lee
      Pages: 4701 - 4711
      Abstract: Antrodia cinnamomea, an endemic basidiomycete used as a health food in Taiwan, is known to synthesize antroquinonols, which were reported to have notable medicinal potential in oncology and immunology. However, the biosynthetic pathway of these compounds is currently unclear. Our previous study showed that a pks63787 knockout mutant of A. cinnamomea (∆pks63787) is deficient in the biosynthesis of several aromatic metabolites. In this study, we pointed by phylogenetic analysis that pks63787 likely encodes an orsellinic acid synthase. Moreover, amendment of the cultural medium with orsellinic acid not only restores the ability of ∆pks63787 to produce its major pigment and other deficient metabolites, e.g., antroquinonols, but also enhances the productivity of several antroquinonols, including two new compounds 2 and 3. These results provide direct evidence that the PKS63787 is involved in the biosynthesis of antroquinonols and confirmed our hypothesis that the 6-methylcyclohexenone moiety was synthesized via the PKS63787-mediated polyketide pathway. In conclusion, PKS63787 might function as orsellinic acid synthase and orsellinic acid is an important precursor indispensable for the biosynthesis of the major pigment and antroquinonols in A. cinnamomea. To facilitate further basic or applied study, a putative biosynthesis pathway map of antroquinonols is proposed.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8196-6
      Issue No: Vol. 101, No. 11 (2017)
       
  • Genetically engineered Escherichia coli Nissle 1917 synbiotic counters
           fructose-induced metabolic syndrome and iron deficiency
    • Authors: Archana Somabhai Chaudhari; Ruma Raghuvanshi; G. Naresh Kumar
      Pages: 4713 - 4723
      Abstract: Consumption of fructose leads to metabolic syndrome, but it is also known to increase iron absorption. Present study investigates the effect of genetically modified Escherichia coli Nissle 1917 (EcN) synbiotic along with fructose on non-heme iron absorption. Charles foster rats weighing 150–200 g were fed with iron-deficient diet for 2 months. Probiotic treatment of EcN (pqq) and EcN (pqq-glf-mtlK) was given once per week, 109 cells after 2 months with fructose in drinking water. Iron levels, blood, and liver parameters for oxidative stress, hyperglycemia, and dyslipidemia were estimated. Transferrin-bound iron levels in the blood decreased significantly after 10 weeks of giving iron-deficient diet. Probiotic treatment of EcN (pqq-glf-mtlK) and fructose together led to the restoration of normal transferrin-bound iron levels and blood and hepatic antioxidant levels as compared to iron-deficient control group. The probiotic also led to the restoration of body weight along with levels of serum and hepatic lipid, blood glucose, and antioxidant in the blood and liver as compared to iron-deficient control group. Restoration of liver injury marker enzymes was also seen. Administration of EcN-producing PQQ and mannitol dehydrogenase enzyme together with fructose led to increase in the transferrin-bound iron levels in the blood and amelioration of consequences of metabolic syndrome caused due to fructose consumption.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8207-7
      Issue No: Vol. 101, No. 11 (2017)
       
  • Environmental and metabolic parameters affecting the uric acid production
           of Arxula adeninivorans
    • Authors: Jonathan Williams; Anke Trautwein-Schult; Gotthard Kunze; Kim Baronian
      Pages: 4725 - 4736
      Abstract: The yeast Arxula adeninivorans has previously been shown to naturally secrete the redox molecule uric acid (UA). This property suggested that A. adeninivorans may be capable of functioning as the catalyst for a mediator-less yeast-based microbial fuel cell (MFC) if the level of UA it secretes could be increased. We investigated the effects of a number of parameters on the level of UA produced by A. adeninivorans. The concentration of UA accumulated in a dense cell suspension of A. adeninivorans after 20 h incubation was shown to be significantly lower in aerated suspensions compared with that in anaerobic conditions due to UA being rapidly oxidised by dissolved oxygen. The presence of carbon sources, glucose and glycerol, both caused a reduction in UA production compared with that in starvation conditions. The transgenic A. adeninivorans strain, G1221 (auox), showed higher UA production at 37 °C, but at 47 °C, the wild-type LS3 accumulated higher concentrations; however, elevated temperatures also resulted in very high cell mortality rates. An initial buffer pH of 8 caused a higher concentration of UA to accumulate, but high pH is detrimental to cell metabolism and the cells actively work to lower the pH of their environment. It appears that most parameters which increase the amount of UA produced by A. adeninivorans have concomitant disadvantages for cell metabolism, and as such, its potential as a self-mediating MFC catalyst seems doubtful.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8199-3
      Issue No: Vol. 101, No. 11 (2017)
       
  • Direct quantification of lipopeptide biosurfactants in biological samples
           
    • Authors: Piotr Biniarz; Marcin Łukaszewicz
      Pages: 4747 - 4759
      Abstract: The rapid and accurate quantification of biosurfactants in biological samples is challenging. In contrast to the orcinol method for rhamnolipids, no simple biochemical method is available for the rapid quantification of lipopeptides. Various liquid chromatography (LC) methods are promising tools for relatively fast and exact quantification of lipopeptides. Here, we report strategies for the quantification of the lipopeptides pseudofactin and surfactin in bacterial cultures using different high- (HPLC) and ultra-performance liquid chromatography (UPLC) systems. We tested three strategies for sample pretreatment prior to LC analysis. In direct analysis (DA), bacterial cultures were injected directly and analyzed via LC. As a modification, we diluted the samples with methanol and detected an increase in lipopeptide recovery in the presence of methanol. Therefore, we suggest this simple modification as a tool for increasing the accuracy of LC methods. We also tested freeze-drying followed by solvent extraction (FDSE) as an alternative for the analysis of “heavy” samples. In FDSE, the bacterial cultures were freeze-dried, and the resulting powder was extracted with different solvents. Then, the organic extracts were analyzed via LC. Here, we determined the influence of the extracting solvent on lipopeptide recovery. HPLC methods allowed us to quantify pseudofactin and surfactin with run times of 15 and 20 min per sample, respectively, whereas UPLC quantification was as fast as 4 and 5.5 min per sample, respectively. Our methods provide highly accurate measurements and high recovery levels for lipopeptides. At the same time, UPLC-MS provides the possibility to identify lipopeptides and their structural isoforms.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8272-y
      Issue No: Vol. 101, No. 11 (2017)
       
  • Fungi-based treatment of brewery wastewater—biomass production and
           nutrient reduction
    • Authors: M. Hultberg; H. Bodin
      Pages: 4791 - 4798
      Abstract: The beer-brewing process produces high amounts of nutrient-rich wastewater, and the increasing number of microbreweries worldwide has created a need for innovative solutions to deal with this waste. In the present study, fungal biomass production and the removal of organic carbon, phosphorus and nitrogen from synthetic brewery wastewater were studied. Different filamentous fungi with a record of safe use were screened for growth, and Trametes versicolor, Pleurotus ostreatus and Trichoderma harzianum were selected for further work. The highest biomass production, 1.78 ± 0.31 g L−1 of dry weight, was observed when P. ostreatus was used for the treatment, while T. harzianum demonstrated the best capability for removing nutrients. The maximum reduction of chemical oxygen demand, 89% of the initial value, was observed with this species. In the removal of total nitrogen and phosphorus, no significant difference was observed between the species, while removal of ammonium varied between the strains. The maximum reduction of ammonium, 66.1% of the initial value, was also found in the T. harzianum treatment. It can be concluded that all treatments provided significant reductions in all water-quality parameters after 3 days of growth and that the utilisation of filamentous fungi to treat brewery wastewater, linked to a deliberate strategy to use the biomass produced, has future potential in a bio-based society.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8185-9
      Issue No: Vol. 101, No. 11 (2017)
       
  • Development and application of a rapid, user-friendly, and inexpensive
           method to detect Dehalococcoides sp. reductive dehalogenase genes from
           groundwater
    • Authors: Yogendra H. Kanitkar; Robert D. Stedtfeld; Paul B. Hatzinger; Syed A. Hashsham; Alison M. Cupples
      Pages: 4827 - 4835
      Abstract: TaqMan probe-based quantitative polymerase chain reaction (qPCR) specific to the biomarker reductive dehalogenase (RDase) genes is a widely accepted molecular biological tool (MBT) for determining the abundance of Dehalococcoides sp. in groundwater samples from chlorinated solvent-contaminated sites. However, there are significant costs associated with this MBT. In this study, we describe an approach that requires only low-cost laboratory equipment (a bench top centrifuge and a water bath) and requires less time and resources compared to qPCR. The method involves the concentration of biomass from groundwater, without DNA extraction, and loop-mediated isothermal amplification (LAMP) of the cell templates. The amplification products are detected by a simple visual color change (orange/green). The detection limits of the assay were determined using groundwater from a contaminated site. In addition, the assay was tested with groundwater from three additional contaminated sites. The final approach to detect RDase genes, without DNA extraction or a thermal cycler, was successful to 1.8 × 105 gene copies per L for vcrA and 1.3 × 105 gene copies per L for tceA. Both values are below the threshold recommended for effective in situ dechlorination.
      PubDate: 2017-06-01
      DOI: 10.1007/s00253-017-8203-y
      Issue No: Vol. 101, No. 11 (2017)
       
  • Assessment of the horizontal transfer of functional genes as a suitable
           approach for evaluation of the bioremediation potential of
           petroleum-contaminated sites: a mini-review
    • Authors: Aiyoub Shahi; Bahar Ince; Sevcan Aydin; Orhan Ince
      Abstract: Abstract Petroleum sludge contains recalcitrant residuals. These compounds because of being toxic to humans and other organism are of the major concerns. Therefore, petroleum sludge should be safely disposed. Physicochemical methods which are used by this sector are mostly expensive and need complex devices. Bioremediation methods because of being eco-friendly and cost-effective overcome most of the limitations of physicochemical treatments. Microbial strains capable to degrade petroleum hydrocarbons are practically present in all soils and sediments and their population density increases in contact with contaminants. Bacterial strains cannot degrade alone all kinds of petroleum hydrocarbons, rather microbial consortium should collaborate with each other for degradation of petroleum hydrocarbon mixtures. Horizontal transfer of functional genes between bacteria plays an important role in increasing the metabolic potential of the microbial community. Therefore, selecting a suitable degrading gene and tracking its horizontal transfer would be a useful approach to evaluate the bioremediation process and to assess the bioremediation potential of contaminated sites.
      PubDate: 2017-05-12
      DOI: 10.1007/s00253-017-8306-5
       
 
 
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