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Publisher: Springer-Verlag   (Total: 2345 journals)

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Showing 1 - 200 of 2345 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: 20, SJR: 1.192, h-index: 74)
AAPS PharmSciTech     Hybrid Journal   (Followers: 6, 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: 7, SJR: 1.818, h-index: 22)
Acta Informatica     Hybrid Journal   (Followers: 5, SJR: 0.524, h-index: 32)
Acta Mathematica     Hybrid Journal   (Followers: 11, 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: 19, SJR: 0.898, h-index: 52)
Acta Mechanica Sinica     Hybrid Journal   (Followers: 5, 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: 15, 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: 9, 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: 9, 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: 19, 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: 6, 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: 3, 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: 12, 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: 16, 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: 14, 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 Ophthalmology     Hybrid Journal   (Followers: 9)
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: 47, 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: 12, 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: 17, 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 and Museum Informatics     Hybrid Journal   (Followers: 120)
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: 17, 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: 9, SJR: 0.288, h-index: 25)
Artificial Intelligence Review     Hybrid Journal   (Followers: 14, SJR: 0.948, h-index: 48)
Artificial Life and Robotics     Hybrid Journal   (Followers: 7, 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: 12, 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: 20, SJR: 0.58, h-index: 30)

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Journal Cover Annals of Microbiology
  [SJR: 0.402]   [H-I: 26]   [9 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1590-4261 - ISSN (Online) 1869-2044
   Published by Springer-Verlag Homepage  [2345 journals]
  • Abundance and diversity of ammonia-oxidizing archaea in a biological
           aerated filter process
    • Authors: Hongyi Chen; Wenbiao Jin; Zhaoyun Liang; Abd El-Fatah Abomohra; Xu Zhou; Renjie Tu; Songfang Han
      Pages: 405 - 416
      Abstract: Ammonia-oxidizing archaea (AOA) represent an important group of ammonia-oxidizing microorganisms that are able to convert ammonia to nitrite, a function which is crucial for the removal of nitrogen from wastewater. In this study, we investigated the abundance and diversity of AOA in a full-scale wastewater treatment plant (WWTP) which used a biological aerated filter (BAF) as the main processing mode. According to the quantitative PCR results, AOA clearly outnumbered ammonia-oxidizing bacteria (AOB) during the whole process. The abundance of AOA amoA genes in the filter layer of BAF was highest with the value varied from 6.32 × 103 to 3.8 × 104 copies/ng DNA. The highest abundance of AOB amoA genes was 1.32 × 102 copies/ng DNA, recorded in the effluent of the ACTIFLO® settling tank. The ratios of AOA/AOB in the WWTP were maintained at two or three orders of magnitude. Most AOA obtained from the WWTP fell within the Nitrosopumilus cluster. The abundance of AOA and AOB was significantly correlated with ammonium nitrogen concentrations and pH value. The community structure of AOA was significantly influenced by dissolved oxygen concentrations, pH value and chemical oxygen demand.
      PubDate: 2017-05-26
      DOI: 10.1007/s13213-017-1272-4
      Issue No: Vol. 67, No. 6 (2017)
       
  • Functional characterization of two alkane hydroxylases in a versatile
           Pseudomonas aeruginosa strain NY3
    • Authors: Yan Wang; Maiqian Nie; Yi Wan; Xiaoting Tian; Hongyun Nie; Jing Zi; Xia Ma
      Abstract: Pseudomonas aeruginosa strain NY3 has an extraordinary capacity to utilize a wide range of substrates, including n–alkanes of lengths C5 to C34, aromatic compounds, phenols, diesel and crude oil, and it can produce a variety of small bioactive molecules, including rhamnolipids, which can enhance its metabolic capacity for hydrophobic organic pollutants. This capacity makes NY3 a good candidate for use in environmental pollution remediation. Alkane hydroxylases catalyze both the initial and rate-limiting step of the terminal oxidation of n–alkanes. To better understand the genetic mechanisms by which P. aeruginosa NY3 degrades such a wide range of n–alkanes, two putative coding genes of alkane hydroxylases were functionally characterized using a gene-knockout approach with three different degradation systems. The single n–alkane test indicated that the hydroxylase AlkB2 acted in the early growth phase and played a major role in the utilization of C12–C18. However, a double mutant showed a trend towards recovery when C20–C24 were used as sole carbon source. This suggests that there are other enzymes capable of utilizing n–alkanes longer than C20. Tests of both artificial n–alkanes mixture and crude oil-containing waste water showed similar results, suggesting that both AlkB1 and AlkB2 are involved in n–alkane degradation, and, moreover, that AlkB2 plays a major role. Finally, given the wider functional range of both AlkBs in the mixture of n–alkanes compared to that of single n–alkanes, these results hint at co-metabolism.
      PubDate: 2017-06-08
      DOI: 10.1007/s13213-017-1271-5
       
  • Tandem mass tag-based quantitative proteomics analyses reveal the response
           of Bacillus licheniformis to high growth temperatures
    • Authors: Zixing Dong; Zhixin Chen; Hongbin Wang; Kangming Tian; Peng Jin; Xiaoguang Liu; Nokuthula Peace Mchunu; Kugenthiren Permaul; Suren Singh; Dandan Niu; Zhengxiang Wang
      Abstract: As the optimal growth temperature of Bacillus licheniformis is relatively higher than many other industrial bacteria, its use for industrial production can reduce contamination and minimize cooling and product recovery costs during fermentation processes. However, little is known about the thermotolerance of this important bacterial species. To investigate the underlying mechanism, strains B. licheniformis ATCC 14580 and B186 were cultivated at their own optimal growth temperature (42 °C and 50 °C) and higher temperature (60 °C), respectively, and tandem mass tags (TMT)-based quantitative proteome analysis and bioinformatics tools were employed to identify differentially expressed proteins. A total of 21 differential proteins were identified and shown to participate in a wide range of biological processes, including protein refolding, amino acid and fatty acid metabolism, etc. Hence, the ability of B. licheniformis to exhibit optimal growth at high temperatures may depend on invoking its intrinsic “heat-against” proteomic mechanism for long-term viability. Our results may assist the genetic improvement of industrial strains of this important Bacillus specie.
      PubDate: 2017-06-05
      DOI: 10.1007/s13213-017-1279-x
       
  • Diversity and dynamics of the bacterial community involved in pig manure
           biodegradation in a microbial fermentation bed system
    • Authors: Qianqian Chen; Bo Liu; Jieping Wang; Jianmei Che; Guohong Liu; Xiong Guan
      Abstract: Overproduction of livestock manures with unpleasant odors causes significant environmental problems. The microbial fermentation bed (MFB) system is considered an effective approach to recycling utilization of agricultural byproducts and pig manure (PM). To gain a better understanding of bacterial communities present during the degradation of PM in MFB, the PM bacterial community was evaluated at different fermentation stages using 16S rRNA high throughput sequencing technology. The heatmap plot clustered five samples into short-term fermentation stage of 0–10 days and long-term fermentation stage of 15–20 days. The most abundant OTUs at the phylum level were Firmicutes, Actinobacteria and Proteobacteria in the long-term fermentation stage of PM, whereas Firmicutes, Bacteroidetes, and Proteobacteria predominated in the short-term fermentation stage of PM. At the genus level, organic degradation strains, such as Corynebacterium, Bacillus, Virgibacillus, Pseudomonas, Actinobacteria, Lactobacillus, Pediococcus were the predominate genera at the long-term fermentation stage, but were found only rarely in the short-term fermentation stage. C/N ratios increased and the concentration of the unpleasant odor substance 3-hydroxy-5-methylisoxazole (3-MI) decreased with prolonged period of fermentation. Redundancy analysis (RDA) demonstrated that the relative abundance of Firmicutes, Actinobacteria, Acidobacteria and Proteobacteria had a close relationship with degradation of 3-MI and increasing C/N ratio. These results provide valuable additional information about bacterial community composition during PM biodegradation in animal husbandry.
      PubDate: 2017-06-03
      DOI: 10.1007/s13213-017-1278-y
       
  • Radio-protective and antioxidative activities of astaxanthin from newly
           isolated radio-resistant bacterium Deinococcus sp. strain WMA-LM9
    • Authors: Wasim Sajjad; Mazoor Ahmad; Salman Khan; Sunniya Ilyas; Fariha Hasan; Cem Celik; Kerry McPhail; Aamer Ali Shah
      Abstract: A radio-resistant bacterium, designated as strain WMA-LM9, was isolated from desert soil. 16S rRNA gene sequencing indicated that the bacterium belongs to genus Deinococcus with maximum similarity to Deinococcus radiopugnans. Deinococcus sp. strain WMA-LM9 was found to be resistant to a ultraviolet (UV) dose of 5 × 103 J/m2, hydrogen peroxide (50 mM) and mitomycin C (10 μg/ml). A carotenoid pigment was extracted using chloroform/methanol/acetone (7:5:3) and purified by high-performance liquid chromatography on a C18 analytical column. The compound was characterised as mono-esterified astaxanthin by 1H, 13C nuclear magnetic resonance and mass spectrometry. It was tested for antioxidant activity, total flavonoids and phenolic content, radioprotective potential in correlation to the prevention of protein oxidation and DNA strand breaks in vitro. The carotenoid pigment showed a very potent antioxidant activity and significantly stronger scavenging ability against superoxides, with an IC50 (concentration causing 50% inhibition of the desired activity) of 41.6 μg/ml. The total phenolic and flavonoid contents were 12.1 and 7.4 μg in terms of gallic acid and quercetin equivalents per milligram of dried mass, respectively. astaxanthin also showed a higher inhibitory action against oxidative damage to collagen, elastin and bovine serum albumin than did β-carotene. The carotenoid also inhibited breaks to DNA strands, as indicated by the results of the DNA damage prevention assay. We conclude that astaxanthin from Deinococcus sp. strain WMA-LM9 has protective effects against radiation-mediated cell damage, and it also protects cellular protein and DNA against oxidative stress and other anti-oxidant activities.
      PubDate: 2017-05-29
      DOI: 10.1007/s13213-017-1269-z
       
  • Comparative transcriptomic analysis of Listeria monocytogenes reveals
           upregulation of stress genes and downregulation of virulence genes in
           response to essential oil extracted from Baccharis psiadioides
    • Authors: Luiza Pieta; Frank Lino Guzman Escudero; Ana Paula Jacobus; Kamila Patikowski Cheiran; Jeferson Gross; Maria Lisseth Eguiluz Moya; Geraldo Luiz Gonçalves Soares; Rogério Margis; Ana Paula Guedes Frazzon; Jeverson Frazzon
      Abstract: Listeria monocytogenes is a pathogenic microorganism in humans and is frequently transmitted by food. Methods to control the presence of Listeria in foods are necessary. In the present study, transcriptomics of L. monocytogenes grown in the presence of essential oil extracted from Baccharis psiadioides were studied by RNA sequencing and reverse transcription quantitative polymerase chain reaction (RT-qPCR) experiments. The results obtained indicate that essential oil of B. psiadioides has potential bacteriostatic activity at the concentration tested, affecting Listeria cells functioning and development. Responses of the microorganism included upregulation of stress genes and downregulation of virulence genes, such as actA, hly and prfA, indicating a decrease in virulence and in the capacity of the microorganism to cause infection. Thus, the results presented here allow us to conclude that B. psiadioides essential oil may be an alternative means of controlling microorganisms proliferating in foods.
      PubDate: 2017-05-28
      DOI: 10.1007/s13213-017-1277-z
       
  • Bacterial diversity in Shahu lake, northwest China is significantly
           affected by nutrient composition rather than location
    • Authors: Jing-Yu Li; Yi-Fei Zhang; Zhou Yang; Meng Wang
      Abstract: Shallow lakes around the world are important aquatic ecosystems, yet our understanding of the relationship between the bacterial communities and their driving forces in these habitats remains elusive. We used the Illumina MiSeq platform to meta-sequence the V3–V4 regions of 16S rRNA gene amplicons to characterize bacterial community structure and diversity in relation to environmental factors in Shahu Lake located in Yinchuan plain, northwest China. We found that Shahu Lake, as a typical representative of shallow lakes, has well-mixed water that harbors major bacterial groups including Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, Chloroflexi, RF3, and Planctomycetes. Community structure is similar from the perspective of alpha-diversity and different in terms of beta-diversity. Compared to spatial effects, total carbon plays a more important role in shifting bacterial structure in the lake, followed by total nitrogen and total phosphorus. In summary, nutrients, rather than locations, might be a key driving force in bacterial structure shift in shallow small lakes.
      PubDate: 2017-05-26
      DOI: 10.1007/s13213-017-1276-0
       
  • Salicylate degradation by a cold-adapted Pseudomonas sp.
    • Authors: Eunsol Ahn; Ki Young Choi; Beom Sik Kang; Gerben J. Zylstra; Dockyu Kim; Eungbin Kim
      Abstract: Pseudomonas sp. strain MC1 was characterized as a cold-adapted, naphthalene-degrading bacterium that is able to grow in a broad temperature range of 5–30°C. MC1 harbors a catabolic plasmid, designated pYIC1, which is almost identical to the archetypal NAH7 plasmid from the mesophilic bacterium Pseudomonas putida G7. On pYIC1, the catabolic genes for naphthalene degradation are clustered in two operons: nahAa-Ab-Ac-Ad-B-F-C-Q-E-D encoding the conversion of naphthalene to salicylate, and nahG-T-H-I-N-L-O-M-K-J encoding the conversion of salicylate through meta-cleavage pathway to pyruvate and acetyl CoA. NahH, the bona fide extradiol dioxygenase in MC1 salicylate metabolism, is thermolabile and is a cold-adapted enzyme. The thermal profiles of the NahH enzyme activities expressed in different hosts indicate the presence of a factor(s) or mechanism(s) to protect the thermolabile NahH enzyme (100% aa identity with MC1 counterpart) in G7. Overall, the results reported in the present work suggest that the thermolabile NahH might be a product of the cold-adaptation process of MC1 and thus contribute to the survival and growth ability of MC1 on salicylate and naphthalene in cold environments.
      PubDate: 2017-05-21
      DOI: 10.1007/s13213-017-1273-3
       
  • Enhancing carotenoid production in Rhodotorula mucilaginosa KC8 by
           combining mutation and metabolic engineering
    • Authors: Qiang Wang; Dong Liu; Qingxiang Yang; Panliang Wang
      Abstract: Rhodotorula mucilaginosa has been considered as a potential industrial yeast due to its unicellular and fast-growing characteristics, and its ability to produce carotenoids, including torularhodin. However, its low total carotenoid production limits its commercial application. In this study, mutation breeding and metabolic engineering were employed to enhance carotenoid production in the R. mucilaginosa strain KC8. After chemical–physical mutagenesis, R. mucilaginosa K4 with a 67% greater concentration of carotenoids (14.47 ± 0.06 mg L−1) than R. mucilaginosa KC8 (8.67 ± 0.07 mg L−1) was obtained. To further enhance carotenoid production, gene HMG1 encoding the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was introduced from another yeast, Saccharomyces cerevisiae, and overexpressed in R. mucilaginosa K4. The carotenoid production of HMG1-gene-overexpression transformant G1 reached 16.98 mg L−1. To relieve the feedback inhibition of ergosterol, and to down-regulate ergosterol synthesis, ketoconazole, an ergosterol synthesis inhibitor, was added at a concentration of 28 mg L−1. The carotenoid production of the transformant G1 reached 19.14 ± 0.09 mg L−1, which was 121% higher than in R. mucilaginosa KC8. This suggests that a combination of chemical–physical mutagenesis, overexpression of the HMG1 gene, and adding ketoconazole is an effective strategy to improve carotenoid production.
      PubDate: 2017-05-20
      DOI: 10.1007/s13213-017-1274-2
       
  • Occurrence and distribution of multiple antibiotic-resistant Enterococcus
           and Lactobacillus spp. from Indian poultry: in vivo transferability of
           their erythromycin, tetracycline and vancomycin resistance
    • Authors: Chandran Preethi; Surya Chandra Rao Thumu; Prakash M. Halami
      Abstract: The objective of this study was to determine the occurrence and distribution of antibiotic resistant (AR) lactic acid bacteria (LAB) in Indian poultry. LAB from poultry farm feces (n = 21) and samples from slaughter houses comprising chicken intestine (n = 46), raw meat (n = 23), and sanitary water (n = 4) were evaluated and compared with those from organic chicken (OC) collected from nearby villages. Screening studies showed 5–7 log units higher erythromycin (ER), tetracycline (TC) and vancomycin (VAN) resistant LAB from conventional poultry chicken (CC) compared to OC. Molecular characterization of isolated cultures (n = 32) with repetitive-PCR profiling and 16S rRNA gene sequencing revealed their taxonomical status as Enterococcus faecium (n = 16), Enterococcus durans (n = 2), Lactobacillus plantarum (n = 10), Lactobacillus pentosus (n = 1) and Lactobacillus salivarius (n = 3). The isolates were found to harbor erm(B), msr(C), msr(A/B), tet(M), tet(L) and tet(K) genes associated with Tn916 and Tn917 family transposons. Expression studies through real-time PCR revealed antibiotic-induced expression of the identified AR genes. In vitro and in vivo conjugational studies revealed transfer of ER and TC resistant (ERR and TCR) genes with transfer frequencies of 10−7 and 10−4 transconjugants recipient−1, respectively. Although no known VAN resistance (VANR) genes were detected, high phenotypic resistance was observed and was transferable to the recipient. From a public health point of view, this study reports Indian poultry as a major source of high levels of AR bacteria contaminating the food chain and the environment. Thus, urgent and determined strategies are needed to control the spread of multiple AR bacteria.
      PubDate: 2017-05-19
      DOI: 10.1007/s13213-017-1270-6
       
  • Lactobacillus plantarum isolated from cheese: production and partial
           characterization of bacteriocin B391
    • Authors: Paulo Fernandes; Daniela Loureiro; Vitor Monteiro; Carla Ramos; Luis Augusto Nero; Svetoslav Dimitrov Todorov; Joana Santos Guerreiro
      Abstract: Lactobacillus plantarum B391, a strain isolated from an artisanal French cheese, is a producer of a bacteriocin, expressing activity against Enterococcus faecalis NCTC 775, Clostridium perfringens NCTC 13170 and several Listeria monocytogenes strains. High stability was recorded after heat treatment at 121 °C for 20 min and when stored at 4 °C for more than 40 days. A challenge test performed in milk for 11 days showed potential for the control of L. monocytogenes. In the presence of the lytic bacteriocin B391, L. monocytogenes cells present numerous morphology modifications of cell shape and surface structure as well as in the cell division pattern, resulting ultimately in lysis. The high level of Listeria growth inhibition obtained in the presence of Lb. plantarum B391, and the stability of B391 bacteriocin for a long period of time, make this strain potentially interesting to use in milk products to increase food safety.
      PubDate: 2017-05-17
      DOI: 10.1007/s13213-017-1275-1
       
  • GC-MS based metabolomics analysis reveals the effects of different
           agitation speeds on the level of proteinogenic amino acids in Lactococcus
           lactis subsp. cremoris MG1363
    • Authors: Shuhaila Sharif; Kamalrul Azlan Azizan; Syarul Nataqain Baharum
      Abstract: Lactococcus lactis subsp. cremoris MG1363 is an opportunistic lactic acid bacterium (LAB) that has emerged as one of the most promising candidate cell factories. The availability of genome-level information and U.S. Federal Drug administration’s designation of ‘generally recognized as safe’ (GRAS) are two of the more important key factors for its wide-ranging applications in numerous biotechnological processes. Several studies have shown that various physiological conditions, such as temperature, salinity and pH, can influence the physiological growth of L. lactis; agitation, in particular, can increase the production of amino acids and fermentation by-products. However, the effect of different agitation speeds on the growth of L. lactis’ has rarely been examined. In the study reported here, we used a gas chromatography–mass spectrometry-based metabolomics approach to investigate the effects of different agitation speeds on the production of proteinogenic amino acids (PAAs) by L. lactis MG1363. Lactococcus lactis MG1363 was grown under four different agitation speeds (50, 100, 150 and 200 rpm) at a constant temperature of 30 °C, and the differences in the specific growth rate and levels of PAAs were determined. Approximately 15 PAAs with concentrations ranging from 0 to 50 mmol/L were detected under all conditions. Partial least squares discriminant analysis (PLS-DA) revealed a distinct difference when L. lactis was incubated at 100 and 150 rpm. Heatmap analysis showed that the levels of pyruvate-, glutamate- and aspartate-based amino acids were varied under the different agitation conditions. The time-series analysis showed an increment of lysine when L. lactis’ cells were cultured with shaking at 50, 100 and 200 rpm. Taken together, these results highlight the changes in the levels of PAAs in L. lactis cells in response to agitation. In addition, the collected dataset will be useful for optimization of 13C-labeling based experiments in L. lactis.
      PubDate: 2017-05-02
      DOI: 10.1007/s13213-017-1268-0
       
  • In silico characterization of a novel dehalogenase (DehHX) from the
           halophile Pseudomonas halophila HX isolated from Tuz Gölü Lake, Turkey:
           insights into a hypersaline-adapted dehalogenase
    • Authors: Mohamed Faraj Edbeib; Roswanira Abdul Wahab; Yilmaz Kaya; Fahrul Huyop
      Abstract: Halogenated compounds represent potential long-term threats to human well-being and health and, therefore, the quest for microorganisms capable of degrading these hazardous substances merits urgent consideration. We have isolated a novel dehalogenase-producing bacterium from the hypersaline environment of Tuz Gölü Lake, Turkey and subsequently identified this isolate as Pseudomonas halophila HX. Under optimal culture conditions (pH 8.0, 15% NaCl, 30 °C, 200 rpm, 96 h culture time), the strain almost completely degraded (99.3%) 2,2-dichloropropionic acid (20 mM). The dehalogenase gene (dehHX) of the bacterium was amplified by PCR, and the deduced amino acid sequence of the DehHX was found to belong to a Group I dehalogenase and to share an 82% sequence identity to the dehalogenase DehI of Pseudomonas putida strain PP3. Interestingly, the pI of DehHX was more acidic (pI 3.89) than those of the non-halophilic dehalogenases (average measured pI 5.95). Homology-based structural modeling revealed that the surface of DehHX was unusually negatively charged due to the higher presence of acidic residues, which accounts for the uncommonly low pI seen in DehHX and explains the mechanism of adaptation that contributes to the exceptional halotolerance of the enzyme. The excess surface acidic residues were beneficial in enhancing the water-binding capacity, a crucial feature for preserving the stability and solubility of DehHX in highly saline conditions. In summary, we suggest that bio-prospecting for halogenated compound-degrading microorganisms in highly saline environments is a practical and safe strategy for the bioremediation of contaminated coastal areas.
      PubDate: 2017-05-02
      DOI: 10.1007/s13213-017-1266-2
       
  • Genomic analysis of type strain Paenibacillus aceti L14 T , a highly
           efficient producer of pyrazines
    • Authors: Pan Li; Xing Gan; Lixin Luo; Bing Du
      Abstract: Paenibacillus aceti L14T (CGMCC 1.15420 = JCM 31170) is a novel species isolated from the solid-state acetic acid fermentation culture of traditional Chinese vinegar. The strain is able to biosynthesize the pyrazines, including 2,3-diisobutylpyrazine, 2-isobutyl-3-methylpyrazine and 1-(5-isobutyl-2-pyrazinyl)-1-propanone. Genome sequencing of L14 was performed to gain insights into the genetic elements involved in the biosynthesis of pyrazines. The genome of L14 contains 5,611,962 bp with a GC content of 47.92 mol%, 5147 protein coding genes, 92 tRNAs, 20 rRNAs and four sRNAs. The strain L14 also contains complete biosynthetic pathways of valine, leucine and isoleucine, and contains genes for encoding threonine dehydratase and ketol-acid reductoisomerase. This genome sequence provides a basis for elucidating the possible mechanism for the biosynthesis of pyrazines.
      PubDate: 2017-04-28
      DOI: 10.1007/s13213-017-1267-1
       
  • RNAi induced silencing of pathogenicity genes of Fusarium spp. for
           vascular wilt management in tomato
    • Authors: Veerubommu Shanmugam; Vandana Sharma; Poonam Bharti; Poonam Jyoti; Sudesh Kumar Yadav; Rashmi Aggarwal; Shekhar Jain
      Abstract: The necessity to develop new strategies for the control of Fusarium wilt of tomato signifies the identification of pathogencity genes and ascertaining their role to use them as molecular tools for fungicide development or to develop transgenics. Semi-quantitative gene expression studies have identified two pathogenicity genes, FOW2 and chsV, reported as ZnII)2Cys6-type transcription regulator and class V chitin synthase, respectively, as potential ones for being secreted all the time. The roles of these genes in the pathogenicity of Fusarium oxysporum and F. solani have been established by RNA interference (RNAi)-induced silencing (knockdown). The silencing vector encoding hairpin RNA of each of the gene fragment was constructed in a two-step PCR-based cloning, and introduced into the fungal genomic DNA. Silencing of either of the genes resulted in less virulent fungal phenotypes with altered physiological characteristics like sporulation and growth on solid media and a reduction in mRNA expression. The results therefore demonstrate the applicability of these pathogenicity genes as useful molecular targets for exploitation in Fusarium wilt control in tomato.
      PubDate: 2017-04-24
      DOI: 10.1007/s13213-017-1265-3
       
  • Production of pectinolytic enzymes pectinase and pectin lyase by Bacillus
           subtilis SAV-21 in solid state fermentation
    • Authors: Simran Jot Kaur; Vijay Kumar Gupta
      Abstract: Pectin-degrading enzymes (pectinase and pectin lyase) were produced in solid state fermentation by Bacillus subtilis SAV-21 isolated from fruit and vegetable market waste soil of Yamuna Nagar, Haryana, India, and identified by 16S rDNA sequencing. Under optimized conditions, maximum production of pectinase (3315 U/gds) and pectin lyase (10.5 U/gds) was recorded in the presence of a combination of orange peel and coconut fiber (4:1), with a moisture content of 60% at 35 °C and pH 4.0 after 4 days and 8 days of incubation, respectively. Pectinase yield was enhanced upon supplementation with galactose and yeast extract, whereas pectin lyase production was unaffected by adding carbon and nitrogen source to the basal medium. Thus, B. subtilis SAV-21 can be exploited for cost-effective production of pectinase and pectin lyase using agro-residues.
      PubDate: 2017-03-28
      DOI: 10.1007/s13213-017-1264-4
       
  • Isolation and characterization of anticancer flavone chrysin
           (5,7-dihydroxy flavone)-producing endophytic fungi from Passiflora
           incarnata L. leaves
    • Authors: Prabukumar Seetharaman; Sathishkumar Gnanasekar; Rajkuberan Chandrasekaran; Gobinath Chandrakasan; Murugan Kadarkarai; Sivaramakrishnan Sivaperumal
      Abstract: Chrysin (5,7-dihydroxy flavone, ChR) is a flavone of plant origin, possessing numerous biomedical properties, such as antimicrobial, anti-inflammatory, anti-diabetic, anxiolytic, hepatoprotective, anti-aging and anticonvulsant activities. In this study, chrysin-producing fungal endophytes (A. alternata KT380662, C. capsici KT373967, and C. taiwanense PI-3 KX580307) were isolated from the leaves of Passiflora incarnata L. and characterised via morphology and internal transcribed spacer (ITS) sequences. Thin layer chromatography and high-performance liquid chromatography profiles of fungal extracts showed Rf values and retention times that closely match those of standard chrysin (ChR). Further, the production of fungal chrysin (FChR) was confirmed through UV-vis spectroscopy, FT-IR, LC-ESI-MS, and 1H1 NMR analysis. Among the isolated strains, A. alternata KT380662 was identified as having a high-level of ChR production, with rates measuring approximately 846 mg L−1. On the other hand, in vitro anticancer and radical scavenging studies proved that FChR has significant cytotoxic activity against human liver carcinoma cells (HepG2). These results clearly imply that the isolated A. alternata KT380662 could serve as an alternative source for the commercial production of ChR, which holds anticancer and radical scavenging activities, and the fungal-derived ChR can be used in chemotherapy or in prodrug development.
      PubDate: 2017-03-22
      DOI: 10.1007/s13213-017-1263-5
       
  • Diversity and composition of bacterial community in the rhizosphere
           sediments of submerged macrophytes revealed by 454 pyrosequencing
    • Authors: Dayong Zhao; Sichen Wang; Rui Huang; Jin Zeng; Feng Huang; Zhongbo Yu
      Abstract: Freshwater lake sediments support a variety of submerged macrophytes that may host groups of bacteria exerting important ecological functions. We collected three kinds of commonly found submerged macrophyte species (Ceratophyllum demersum, Vallisneria spiralis and Elodea nuttallii) to investigate the bacterial community associated with their rhizosphere sediments. High-throughput 454 pyrosequencing and bioinformatics analyses were performed to examine the diversity and composition of the bacterial community. The results obtained indicated that the diversity of the bacterial community associated with the rhizosphere sediments of submerged macrophytes was significantly lower than that of the bulk sediment. Remarkable differences in the bacterial community composition between the rhizosphere and bulk sediments were also observed.
      PubDate: 2017-03-17
      DOI: 10.1007/s13213-017-1262-6
       
  • Biodegradation optimization and metabolite elucidation of Reactive Red 120
           by four different Aspergillus species isolated from soil contaminated with
           industrial effluent
    • Authors: Fuad Ameen; Fatimah Alshehrei
      Abstract: Azo dyes are recalcitrant owing to their xenobiotic nature and exhibit high resistance to degradation processes. In the present study, different Aspergillus species (A. flavus, A. fumigatus, A. niger, and A. terreus) isolated from soil samples contaminated with industrial effluent, collected from Jeddah, Saudi Arabia, were analyzed for azo dye, Reactive Red 120 (RR120) biodegradation. The physicochemical parameters such as carbon (sucrose) and nitrogen (ammonium sulfate) sources, pH, and temperature affecting the biodegradation of RR120 were optimized using central composite design–response surface methodology (CCD-RSM). The maximum RR120 degradation was found to be 84% (predicted) at the optimum level of sucrose (11.73 g/L), ammonium sulfate (1.26 g/L), pH (5.71), and temperature (28.26 °C). Further, the validation results confirmed that the predicted values are in good agreement with the experimental results for RR120 degradation by A. flavus (86%), A. fumigatus (84%), A. niger (85%), and A. terreus (86%). The metabolic product of RR120 after biodegradation by different Aspergillus species was identified as sodium 2-aminobenzenesulfonate. The present study suggests that Aspergillus species are good candidates for azo dye-loaded effluent treatment.
      PubDate: 2017-03-11
      DOI: 10.1007/s13213-017-1259-1
       
  • In vitro assessment of safety and probiotic potential characteristics of
           Lactobacillus strains isolated from water buffalo mozzarella cheese
    • Authors: Sabrina Neves Casarotti; Bruno Moreira Carneiro; Svetoslav Dimitrov Todorov; Luis Augusto Nero; Paula Rahal; Ana Lúcia Barretto Penna
      Abstract: The aim of this study was to evaluate the safety and probiotic potential characteristics of ten Lactobacillus spp. strains (Lactobacillus fermentum SJRP30, Lactobacillus casei SJRP37, SJRP66, SJRP141, SJRP145, SJRP146, and SJRP169, and Lactobacillus delbrueckii subsp. bulgaricus SJRP50, SJRP76, and SJRP149) that had previously been isolated from water buffalo mozzarella cheese. The safety of the strains was analyzed based on mucin degradation, hemolytic activity, resistance to antibiotics and the presence of genes encoding virulence factors. The in vitro tests concerning probiotic potential included survival under simulated gastrointestinal (GI) tract conditions, intestinal epithelial cell adhesion, the presence of genes encoding adhesion, aggregation and colonization factors, antimicrobial activity, and the production of the β-galactosidase enzyme. Although all strains presented resistance to several antibiotics, the resistance was limited to antibiotics to which the strains had intrinsic resistance. Furthermore, the strains presented a limited spread of genes encoding virulence factors and resistance to antibiotics, and none of the strains presented hemolytic or mucin degradation activity. The L. delbrueckii subsp. bulgaricus strains showed the lowest survival rate after exposure to simulated GI tract conditions, whereas all of the L. casei and L. fermentum strains showed good survivability. None of the tested lactobacilli strains presented bile salt hydrolase (BSH) activity, and only L. casei SJRP145 did not produce the β-galactosidase enzyme. The strains showed varied levels of adhesion to Caco-2 cells. None of the cell-free supernatants inhibited the growth of pathogenic target microorganisms. Overall, L. fermentum SJRP30 and L. casei SJRP145 and SJRP146 were revealed to be safe and to possess similar or superior probiotic characteristics compared to the reference strain L. rhamnosus GG (ATCC 53103).
      PubDate: 2017-02-28
      DOI: 10.1007/s13213-017-1258-2
       
 
 
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