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  Subjects -> BIOLOGY (Total: 3193 journals)
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BIOTECHNOLOGY (244 journals)                  1 2 | Last

Showing 1 - 200 of 244 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 8)
Advanced Biomedical Research     Open Access  
Advances in Bioscience and Biotechnology     Open Access   (Followers: 17)
Advances in Genetic Engineering & Biotechnology     Hybrid Journal   (Followers: 9)
Advances in Regenerative Medicine     Open Access   (Followers: 3)
African Journal of Biotechnology     Open Access   (Followers: 6)
Algal Research     Partially Free   (Followers: 11)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 70)
American Journal of Bioinformatics Research     Open Access   (Followers: 7)
American Journal of Polymer Science     Open Access   (Followers: 33)
Amylase     Open Access  
Anadolu University Journal of Science and Technology : C Life Sciences and Biotechnology     Open Access  
Animal Biotechnology     Hybrid Journal   (Followers: 8)
Annales des Sciences Agronomiques     Full-text available via subscription  
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 45)
Applied Biosafety     Hybrid Journal  
Applied Food Biotechnology     Open Access   (Followers: 3)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 67)
Applied Mycology and Biotechnology     Full-text available via subscription   (Followers: 4)
Arthroplasty Today     Open Access   (Followers: 1)
Artificial Cells, Nanomedicine and Biotechnology     Hybrid Journal   (Followers: 1)
Asia Pacific Biotech News     Hybrid Journal   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 9)
Asian Pacific Journal of Tropical Biomedicine     Open Access   (Followers: 2)
Australasian Biotechnology     Full-text available via subscription   (Followers: 1)
Banat's Journal of Biotechnology     Open Access  
BBR : Biochemistry and Biotechnology Reports     Open Access   (Followers: 5)
Beitr?ge zur Tabakforschung International/Contributions to Tobacco Research     Open Access   (Followers: 3)
Bio-Algorithms and Med-Systems     Hybrid Journal   (Followers: 2)
Bio-Research     Full-text available via subscription   (Followers: 4)
Bioactive Materials     Open Access   (Followers: 1)
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (Followers: 4)
Biocybernetics and Biological Engineering     Full-text available via subscription   (Followers: 5)
Bioethics UPdate     Hybrid Journal   (Followers: 1)
Biofuels     Hybrid Journal   (Followers: 11)
Biofuels Engineering     Open Access   (Followers: 1)
Biological & Pharmaceutical Bulletin     Full-text available via subscription   (Followers: 4)
Biological Cybernetics     Hybrid Journal   (Followers: 10)
Biomarkers and Genomic Medicine     Open Access   (Followers: 3)
Biomaterials Research     Open Access   (Followers: 4)
BioMed Research International     Open Access   (Followers: 4)
Biomédica     Open Access  
Biomedical and Biotechnology Research Journal     Open Access  
Biomedical Engineering Research     Open Access   (Followers: 6)
Biomedical Glasses     Open Access  
Biomedical Reports     Full-text available via subscription  
BioMedicine     Open Access  
Biomedika     Open Access  
Bioprinting     Hybrid Journal   (Followers: 1)
Bioresource Technology Reports     Hybrid Journal   (Followers: 1)
Bioscience, Biotechnology, and Biochemistry     Hybrid Journal   (Followers: 21)
Biosensors Journal     Open Access  
Biosimilars     Open Access   (Followers: 1)
Biosurface and Biotribology     Open Access  
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
BioTechniques : The International Journal of Life Science Methods     Full-text available via subscription   (Followers: 28)
Biotechnologia Acta     Open Access   (Followers: 1)
Biotechnologie, Agronomie, Société et Environnement     Open Access   (Followers: 2)
Biotechnology     Open Access   (Followers: 8)
Biotechnology & Biotechnological Equipment     Open Access   (Followers: 4)
Biotechnology Advances     Hybrid Journal   (Followers: 34)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 44)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 160)
Biotechnology and Bioprocess Engineering     Hybrid Journal   (Followers: 6)
Biotechnology and Genetic Engineering Reviews     Hybrid Journal   (Followers: 13)
Biotechnology and Health Sciences     Open Access   (Followers: 1)
Biotechnology and Molecular Biology Reviews     Open Access   (Followers: 2)
Biotechnology Annual Review     Full-text available via subscription   (Followers: 5)
Biotechnology for Biofuels     Open Access   (Followers: 10)
Biotechnology Frontier     Open Access   (Followers: 2)
Biotechnology Journal     Hybrid Journal   (Followers: 17)
Biotechnology Law Report     Hybrid Journal   (Followers: 4)
Biotechnology Letters     Hybrid Journal   (Followers: 34)
Biotechnology Progress     Hybrid Journal   (Followers: 41)
Biotechnology Reports     Open Access  
Biotechnology Research International     Open Access   (Followers: 1)
Biotechnology Techniques     Hybrid Journal   (Followers: 10)
Biotecnología Aplicada     Open Access  
Bioteknologi (Biotechnological Studies)     Open Access  
BIOTIK : Jurnal Ilmiah Biologi Teknologi dan Kependidikan     Open Access  
Biotribology     Hybrid Journal   (Followers: 1)
BMC Biotechnology     Open Access   (Followers: 17)
Cell Biology and Development     Open Access  
Chinese Journal of Agricultural Biotechnology     Full-text available via subscription   (Followers: 4)
Communications in Mathematical Biology and Neuroscience     Open Access  
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computer Methods and Programs in Biomedicine     Hybrid Journal   (Followers: 8)
Copernican Letters     Open Access   (Followers: 1)
Critical Reviews in Biotechnology     Hybrid Journal   (Followers: 20)
Crop Breeding and Applied Biotechnology     Open Access   (Followers: 3)
Current Bionanotechnology     Hybrid Journal  
Current Biotechnology     Hybrid Journal   (Followers: 4)
Current Opinion in Biomedical Engineering     Hybrid Journal   (Followers: 1)
Current Opinion in Biotechnology     Hybrid Journal   (Followers: 55)
Current Pharmaceutical Biotechnology     Hybrid Journal   (Followers: 9)
Current Research in Bioinformatics     Open Access   (Followers: 13)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Current trends in Biotechnology and Pharmacy     Open Access   (Followers: 8)
DNA and RNA Nanotechnology     Open Access  
EBioMedicine     Open Access  
Electronic Journal of Biotechnology     Open Access  
Entomologia Generalis     Full-text available via subscription   (Followers: 1)
Environmental Science : Processes & Impacts     Full-text available via subscription   (Followers: 4)
Experimental Biology and Medicine     Hybrid Journal   (Followers: 3)
Folia Medica Indonesiana     Open Access  
Food Bioscience     Hybrid Journal  
Food Biotechnology     Hybrid Journal   (Followers: 9)
Food Science and Biotechnology     Hybrid Journal   (Followers: 8)
Frontiers in Bioengineering and Biotechnology     Open Access   (Followers: 6)
Frontiers in Systems Biology     Open Access   (Followers: 2)
Fungal Biology and Biotechnology     Open Access   (Followers: 2)
GM Crops and Food: Biotechnology in Agriculture and the Food Chain     Full-text available via subscription   (Followers: 1)
GSTF Journal of BioSciences     Open Access  
HAYATI Journal of Biosciences     Open Access  
Horticultural Biotechnology Research     Open Access  
Horticulture, Environment, and Biotechnology     Hybrid Journal   (Followers: 11)
IEEE Transactions on Molecular, Biological and Multi-Scale Communications     Hybrid Journal   (Followers: 1)
IET Nanobiotechnology     Hybrid Journal   (Followers: 2)
IN VIVO     Full-text available via subscription   (Followers: 4)
Indian Journal of Biotechnology (IJBT)     Open Access   (Followers: 2)
Indonesia Journal of Biomedical Science     Open Access   (Followers: 2)
Indonesian Journal of Biotechnology     Open Access   (Followers: 1)
Indonesian Journal of Medicine     Open Access  
Industrial Biotechnology     Hybrid Journal   (Followers: 18)
International Biomechanics     Open Access  
International Journal of Bioinformatics Research and Applications     Hybrid Journal   (Followers: 14)
International Journal of Biomechatronics and Biomedical Robotics     Hybrid Journal   (Followers: 4)
International Journal of Biomedical Research     Open Access   (Followers: 2)
International Journal of Biotechnology     Hybrid Journal   (Followers: 5)
International Journal of Biotechnology and Molecular Biology Research     Open Access   (Followers: 4)
International Journal of Biotechnology for Wellness Industries     Partially Free   (Followers: 1)
International Journal of Environment, Agriculture and Biotechnology     Open Access   (Followers: 5)
International Journal of Functional Informatics and Personalised Medicine     Hybrid Journal   (Followers: 4)
International Journal of Medicine and Biomedical Research     Open Access   (Followers: 1)
International Journal of Nanotechnology and Molecular Computation     Full-text available via subscription   (Followers: 3)
International Journal of Radiation Biology     Hybrid Journal   (Followers: 4)
Iranian Journal of Biotechnology     Open Access  
ISABB Journal of Biotechnology and Bioinformatics     Open Access  
Italian Journal of Food Science     Open Access   (Followers: 1)
JMIR Biomedical Engineering     Open Access  
Journal of Biometrics & Biostatistics     Open Access   (Followers: 3)
Journal of Bioterrorism & Biodefense     Open Access   (Followers: 6)
Journal of Petroleum & Environmental Biotechnology     Open Access   (Followers: 1)
Journal of Advanced Therapies and Medical Innovation Sciences     Open Access  
Journal of Advances in Biotechnology     Open Access   (Followers: 5)
Journal Of Agrobiotechnology     Open Access  
Journal of Analytical & Bioanalytical Techniques     Open Access   (Followers: 7)
Journal of Animal Science and Biotechnology     Open Access   (Followers: 4)
Journal of Applied Biomedicine     Open Access   (Followers: 2)
Journal of Applied Biotechnology     Open Access   (Followers: 2)
Journal of Applied Biotechnology Reports     Open Access   (Followers: 2)
Journal of Applied Mathematics & Bioinformatics     Open Access   (Followers: 5)
Journal of Biologically Active Products from Nature     Hybrid Journal   (Followers: 1)
Journal of Biomaterials and Nanobiotechnology     Open Access   (Followers: 6)
Journal of Biomedical Photonics & Engineering     Open Access  
Journal of Biomedical Practitioners     Open Access  
Journal of Bioprocess Engineering and Biorefinery     Full-text available via subscription  
Journal of Bioprocessing & Biotechniques     Open Access  
Journal of BioScience and Biotechnology     Open Access  
Journal of Biosecurity Biosafety and Biodefense Law     Hybrid Journal   (Followers: 3)
Journal of Biotechnology     Hybrid Journal   (Followers: 63)
Journal of Biotechnology and Strategic Health Research     Open Access   (Followers: 1)
Journal of Chemical and Biological Interfaces     Full-text available via subscription   (Followers: 1)
Journal of Chemical Technology & Biotechnology     Hybrid Journal   (Followers: 9)
Journal of Chitin and Chitosan Science     Full-text available via subscription   (Followers: 1)
Journal of Colloid Science and Biotechnology     Full-text available via subscription  
Journal of Commercial Biotechnology     Full-text available via subscription   (Followers: 6)
Journal of Crop Science and Biotechnology     Hybrid Journal   (Followers: 3)
Journal of Ecobiotechnology     Open Access  
Journal of Essential Oil Research     Hybrid Journal   (Followers: 2)
Journal of Experimental Biology     Full-text available via subscription   (Followers: 25)
Journal of Genetic Engineering and Biotechnology     Open Access   (Followers: 5)
Journal of Ginseng Research     Open Access  
Journal of Industrial Microbiology and Biotechnology     Hybrid Journal   (Followers: 18)
Journal of Integrative Bioinformatics     Open Access  
Journal of Medical Imaging and Health Informatics     Full-text available via subscription  
Journal of Molecular Biology and Biotechnology     Open Access  
Journal of Molecular Microbiology and Biotechnology     Full-text available via subscription   (Followers: 13)
Journal of Nano Education     Full-text available via subscription  
Journal of Nanobiotechnology     Open Access   (Followers: 4)
Journal of Nanofluids     Full-text available via subscription   (Followers: 1)
Journal of Organic and Biomolecular Simulations     Open Access  
Journal of Plant Biochemistry and Biotechnology     Hybrid Journal   (Followers: 4)
Journal of Science and Applications : Biomedicine     Open Access  
Journal of the Mechanical Behavior of Biomedical Materials     Hybrid Journal   (Followers: 13)
Journal of Trace Elements in Medicine and Biology     Hybrid Journal   (Followers: 1)
Journal of Tropical Microbiology and Biotechnology     Full-text available via subscription  
Journal of Yeast and Fungal Research     Open Access   (Followers: 1)
Marine Biotechnology     Hybrid Journal   (Followers: 4)
Meat Technology     Open Access  
Messenger     Full-text available via subscription  
Metabolic Engineering Communications     Open Access   (Followers: 4)
Metalloproteinases In Medicine     Open Access  
Microbial Biotechnology     Open Access   (Followers: 10)
MicroMedicine     Open Access   (Followers: 3)
Molecular and Cellular Biomedical Sciences     Open Access   (Followers: 1)
Molecular Biotechnology     Hybrid Journal   (Followers: 13)
Molecular Genetics and Metabolism Reports     Open Access   (Followers: 3)
Nanobiomedicine     Open Access  
Nanobiotechnology     Hybrid Journal   (Followers: 2)

        1 2 | Last

Journal Cover
Applied Microbiology and Biotechnology
Journal Prestige (SJR): 1.182
Citation Impact (citeScore): 4
Number of Followers: 67  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1432-0614 - ISSN (Online) 0175-7598
Published by Springer-Verlag Homepage  [2352 journals]
  • Characterization of downflow hanging sponge reactors with regard to
           structure, process function, and microbial community compositions
    • Authors: Masashi Hatamoto; Tsutomu Okubo; Kengo Kubota; Takashi Yamaguchi
      Pages: 10345 - 10352
      Abstract: The activated sludge (AS) process has been the most widely used process for wastewater treatment despite it has several limitations for its further application and adoption worldwide, owing to unsustainable properties such as high-energy consumption and the production of large amount of excess sludge. To overcome the drawbacks of the AS process, the downflow hanging sponge (DHS) has been developed as an energy-saving and easy-to-maintain alternative. To date, six types of different sponge configurations have been developed and their performances have been evaluated in practical- to full-scale DHS reactors. A large number of studies have been carried out in order to enhance the performance and expand the application fields of the DHS. Transition of this process to the deployment and diffusion stage from the research and development phase is now ongoing in India and Egypt as well as in Japan. Under this situation, concise and state-of-the art review is important for enhancing DHS research and future applications. Herein, we summarize and present the DHS concerning the history of development, the mechanism of treatment, recent studies on its use in the field of wastewater treatment, and the features of microbial community structure.
      PubDate: 2018-12-01
      DOI: 10.1007/s00253-018-9406-6
      Issue No: Vol. 102, No. 24 (2018)
       
  • Virus-like particles of recombinant PCV2b carrying FMDV-VP1 epitopes
           induce both anti-PCV and anti-FMDV antibody responses
    • Authors: Xin Li; Xiuping Meng; Shengnan Wang; Zhiqin Li; Lei Yang; Liqun Tu; Wenzhen Diao; Cheng Yu; Yongli Yu; Chaoying Yan; Liying Wang
      Pages: 10541 - 10550
      Abstract: Mixed infection of porcine circovirus type 2 (PCV2) and foot-and-mouth disease virus (FMDV) is devastating to swine populations. To develop an effective vaccine that can protect the pigs from the infection of PCV2 and FMDV, we used the neutralizing B cell epitope region (aa 135–160) of FMDV to replace the regions aa 123–151 and aa 169–194 of the PCV2b Cap protein to generate a recombinant protein designated as Capfb. The Capfb protein was expressed in Escherichia coli system and the purified Capfb protein assembled into virus-like particles (VLPs) through dialysis. The ability of the Capfb protein to induce effective immune response against FMDV and PCV2b was tested in mice and guinea pigs. The results showed that the Capfb-VLPs could elicit anti-PCV2b and anti-FMDV antibody response in mice and guinea pigs without inducing antibodies against decoy epitope. Moreover, the Capfb-VLPs could enhance the percentage and activation of B cells in lymph nodes when the mice were stimulated with inactivated FMDV or PCV2b. These data suggested that the Capfb-VLPs could be an efficacious candidate antigen for developing a novel PCV2b-FMDV bivalent vaccine.
      PubDate: 2018-12-01
      DOI: 10.1007/s00253-018-9361-2
      Issue No: Vol. 102, No. 24 (2018)
       
  • M cell–targeting strategy enhances systemic and mucosal immune responses
           induced by oral administration of nuclease-producing L. lactis
    • Authors: Keita Takahashi; Ayumu Yano; Shiori Watanabe; Philippe Langella; Luis G. Bermúdez-Humarán; Naoki Inoue
      Pages: 10703 - 10711
      Abstract: Efficient delivery of antigens to the gut-associated lymphoid tissue (GALT) is the most critical step for the induction of mucosal immunity by oral vaccines. As M cells are the main portal for luminal antigens into the GALT, the M cell-targeting of antigens affords a promising strategy toward the development of effective oral vaccines. Lactococcus lactis is a fascinating recombinant host for oral vaccines, as they survive and produce antigens in the gut and have a particularly safe profile for human use. In this study, we developed and evaluated an M cell–targeting oral immunization system using recombinant L. lactis strains. For the purpose, we generated an L. lactis strain that secretes a model antigen fused with the OmpH β1α1 domain of Yersinia enterocolitica, which has been shown to bind to a complement C5a receptor on the M cell surface. As the model antigen, Staphylococcus aureus nuclease was used for fusion, resulting in L. lactis–expressing Nuc-OmpH (LL/Nuc-OmpH). Ex vivo intestinal loop assays showed that the amount of Nuc-OmpH taken up into Peyer’s patches was more than that of the unfused nuclease (Nuc). In addition, oral administration of the recombinant L. lactis strains to mice demonstrated that LL/Nuc-OmpH-induced nuclease-specific fecal IgA and serum IgG titers were significantly higher than those induced by LL/Nuc. These results indicate that OmpH works as an M cell–targeting molecule when fused with antigens secreted from L. lactis and that the M cell–targeting strategy affords a promising platform for L. lactis–based mucosal immunization.
      PubDate: 2018-12-01
      DOI: 10.1007/s00253-018-9427-1
      Issue No: Vol. 102, No. 24 (2018)
       
  • Extremely thermoactive archaeal endoglucanase from a shallow marine
           hydrothermal vent from Vulcano Island
    • Abstract: Already-characterized microbial cellulases have proven to be highly useful for industrial processes, since they can withstand harsh industrial conditions with characteristics such as high thermo- and acid stability. These properties provide promising features for the process of plant biomass degradation and biofuel generation. Nevertheless, the number of known extremely thermoactive archaeal cellulases is low. Hence, the discovery of archaeal cellulases with different characteristics is crucial for the development of efficient and sustainable biorefinery. In this work, the metagenome of a high-temperature enrichment culture from marine environment of Vulcano Island was screened for the presence of novel endoglucanase-encoding genes of archaeal origin. The ORF vul_cel5A was detected, and the deduced protein was characterized as the most thermoactive endoglucanase described to date. Vul_Cel5A was identified as a thermoactive glycoside hydrolase family 5 endoglucanase, with the highest sequence identity (72–75%) to putative endoglucanases from archaeal genera. Vul_Cel5A showed the highest activity at notable 115 °C towards barley β-glucan (210.7 U/mg), and lichenan (209.9 U/mg), and further towards carboxymethyl cellulose (38.6 U/mg) and locust bean gum (83.0 U/mg). The endoglucanase exhibited a half-life time of 46 min at 100 °C and did not show any loss of activity after incubation for 48 h at 75 °C. Furthermore, Vul_Cel5A showed high affinity to barley β-glucan with a Km of 0.52 mg/mL and showed tolerance against various chemical reagents. Due to the outstanding high thermoactivity and thermostability and tolerance to acidic conditions, Vul_Cel5A represents a promising novel archaeal endo-β-glucanase for application in biorefineries for an efficient biomass pre-treatment.
      PubDate: 2018-12-13
       
  • Biochemical characterization and low-resolution SAXS structure of
           two-domain endoglucanase Bl Cel9 from Bacillus licheniformis
    • Abstract: Lignocellulose feedstock constitutes the most abundant carbon source in the biosphere; however, its recalcitrance remains a challenge for microbial conversion into biofuel and bioproducts. Bacillus licheniformis is a microbial mesophilic bacterium capable of secreting a large number of glycoside hydrolase (GH) enzymes, including a glycoside hydrolase from GH family 9 (BlCel9). Here, we conducted biochemical and biophysical studies of recombinant BlCel9, and its low-resolution molecular shape was retrieved from small angle X-ray scattering (SAXS) data. BlCel9 is an endoglucanase exhibiting maximum catalytic efficiency at pH 7.0 and 60 °C. Furthermore, it retains 80% of catalytic activity within a broad range of pH values (5.5–8.5) and temperatures (up to 50 °C) for extended periods of time (over 48 h). It exhibits the highest hydrolytic activity against phosphoric acid swollen cellulose (PASC), followed by bacterial cellulose (BC), filter paper (FP), and to a lesser extent carboxymethylcellulose (CMC). The HPAEC-PAD analysis of the hydrolytic products demonstrated that the end product of the enzymatic hydrolysis is primarily cellobiose, and also small amounts of glucose, cellotriose, and cellotetraose are produced. SAXS data analysis revealed that the enzyme adopts a monomeric state in solution and has a molecular mass of 65.8 kDa as estimated from SAXS data. The BlCel9 has an elongated shape composed of an N-terminal family 3 carbohydrate-binding module (CBM3c) and a C-terminal GH9 catalytic domain joined together by 20 amino acid residue long linker peptides. The domains are closely juxtaposed in an extended conformation and form a relatively rigid structure in solution, indicating that the interactions between the CBM3c and GH9 catalytic domains might play a key role in cooperative cellulose biomass recognition and hydrolysis.
      PubDate: 2018-12-13
       
  • International Space Station conditions alter genomics, proteomics, and
           metabolomics in Aspergillus nidulans
    • Abstract: The first global genomic, proteomic, and secondary metabolomic characterization of the filamentous fungus Aspergillus nidulans following growth onboard the International Space Station (ISS) is reported. The investigation included the A. nidulans wild-type and three mutant strains, two of which were genetically engineered to enhance secondary metabolite production. Whole genome sequencing revealed that ISS conditions altered the A. nidulans genome in specific regions. In strain CW12001, which features overexpression of the secondary metabolite global regulator laeA, ISS conditions induced the loss of the laeA stop codon. Differential expression of proteins involved in stress response, carbohydrate metabolic processes, and secondary metabolite biosynthesis was also observed. ISS conditions significantly decreased prenyl xanthone production in the wild-type strain and increased asperthecin production in LO1362 and CW12001, which are deficient in a major DNA repair mechanism. These data provide valuable insights into the adaptation mechanism of A. nidulans to spacecraft environments.
      PubDate: 2018-12-12
       
  • A short-term stimulation of ethanol enhances the effect of magnetite on
           anaerobic digestion
    • Authors: Caiqin Wang; Weilong Qiao; Hui Chen; Xiangyang Xu; Liang Zhu
      Abstract: Conductive iron oxides (CIO) have been proved recently to facilitate the anaerobic microbial syntrophy based on the direct interspecies electron transfer (DIET) in batch experiments. However, the effect of CIO was always insignificant in anaerobic digestion (AD) reactor especially when the DIET-based syntrophic partners were absent. In this study, the effect of magnetite on performance of AD system with sucrose as a sole carbon source was investigated, but limited enhancement was achieved during the first 36-day operation. The short-term effect of ethanol addition was further studied in the magnetite-amended AD reactor, and results showed that the AD reactor with 10gFe/L micro-sized magnetite (R3) achieved higher performance of COD removal and methane proportion compared with the other reactors (R1 without magnetite; R2 with 2gFe/L micro-sized magnetite; R4 with 2gFe/L nano-sized magnetite). Meanwhile, the pyridoxine in extracellular polymeric substances (EPS) and conductivity of anaerobic sludge from R3 increased more significantly than those of the others. Analysis of high-throughput sequencing indicated that the abundance of archaea increased in sludge from R3 and Methanosarcina responsible for DIET was dominant (63.64%). Additionally, the abundance of potential electroactive bacteria Chloroflexi in R3 was 7.57-fold, 3.61-fold and 7.37-fold as that of R1, R2 and R4, respectively. These results demonstrated that the electroactive microbes and methanogens could be enriched efficiently in anaerobic sludge via synergetic effect of magnetite addition and ethanol short-term stimulation.
      PubDate: 2018-12-12
      DOI: 10.1007/s00253-018-9531-2
       
  • Analysis of enhanced nitrogen removal mechanisms in a validation
           wastewater treatment plant containing anammox bacteria
    • Authors: Qingkun Wang; Chang Ding; Guihe Tao; Jianzhong He
      Abstract: Anammox bacteria have attracted attention due to their apparent importance in saving energy and reducing organic chemical demands. Here, we report the detection and quantification of anammox bacteria with an improved primer set in a validation wastewater treatment plant. The improved primer set was shown to detect a broad range of anammox bacteria (47.3%) facilitating more accurate analyses of nitrogen removal mechanisms. Nitrogen removal efficiency and dominant nitrogen removal mechanisms were compared in the modification-Johannesburg (Mod-JHB), modified Ludzack-Ettinger (MLE) single-feed, and anoxic-oxic-anoxic-oxic (AOAO) step-feed modes. In the Mod-JHB configuration, simultaneous nitrification and denitrification (SND) and anammox were found to be responsible for more than 80% of total inorganic nitrogen (TIN) removal (98.5 ± 0.8% of TIN removal). Decrease of anoxic SRT from 5 to 2.5 days did not have any obvious effect on nitrogen removal or the abundance of functional microorganisms. Microbial batch tests demonstrated that both partial nitrification and dissimilatory nitrate reduction to ammonium (DNRA) were responsible for maintaining the anammox process. Short SRT (2 days) in the aerobic zone may explain the presence of partial nitrification. This study provides insights to the analysis of nitrogen removal mechanisms in validation wastewater treatment plants (WWTPs) aiming for high nitrogen removal efficiency.
      PubDate: 2018-12-11
      DOI: 10.1007/s00253-018-9495-2
       
  • Glycerol inhibition of melanin biosynthesis in the environmental Aeromonas
           salmonicida 34mel T
    • Authors: María Elisa Pavan; Esmeralda Solar Venero; Diego E. Egoburo; Esteban E. Pavan; Nancy I. López; M. Julia Pettinari
      Abstract: The environmental strain Aeromonas salmonicida subsp. pectinolytica 34melT produces abundant melanin through the homogentisate pathway in several culture media, but unexpectedly not when grown in a medium containing glycerol. Using this observation as a starting point, this study investigated the underlying causes of the inhibition of melanin synthesis by glycerol, to shed light on factors that affect melanin production in this microorganism. The effect of different carbon sources on melanin formation was related to the degree of oxidation of their C atoms, as the more reduced substrates delayed melanization more than the more oxidized ones, although only glycerol completely abolished melanin production. Glyphosate, an inhibitor of aromatic amino acid synthesis, did not affect melanization, while bicyclopyrone, an inhibitor of 4-hydroxyphenylpyruvate dioxygenase (Hpd), the enzyme responsible for the synthesis of homogentisate, prevented melanin synthesis. These results showed that melanin production in 34melT depends on the degradation of aromatic amino acids from the growth medium and not on de novo aromatic amino acid synthesis. The presence of glycerol changed the secreted protein profile, but none of the proteins affected could be directly connected with melanin synthesis or transport. Transcription analysis of hpd, encoding the key enzyme for melanin synthesis, showed a clear inhibition caused by glycerol. The results obtained in this work indicate that a significant decrease in the transcription of hpd, together with a more reduced intracellular state, would lead to the abolishment of melanin synthesis observed. The effect of glycerol on melanization can thus be attributed to a combination of metabolic and regulatory effects.
      PubDate: 2018-12-11
      DOI: 10.1007/s00253-018-9545-9
       
  • MdrL, a major facilitator superfamily efflux pump of Listeria
           monocytogenes involved in tolerance to benzalkonium chloride
    • Authors: Xiaobing Jiang; Tao Yu; Yameng Xu; Hailei Wang; Hannu Korkeala; Lei Shi
      Abstract: Efflux pumps are recognized as an important mechanism for decreased susceptibility of benzalkonium chloride (BC) in Listeria monocytogenes. Previous studies showed that the efflux pump MdrL was overexpressed in L. monocytogenes exposed to BC. In the present work, we aimed to clarify the role of MdrL in tolerance to BC and environmental stresses including acid, alkali, osmotic, ethanol, and oxidative stresses, as well as resistance to other antimicrobial agents in L. monocytogenes EGD-e. In addition, regulation of the expression of mdrL by LadR was investigated. Gene deletion mutants were constructed by homologous recombination strategy. For the wild-type and mutant strains, minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by the agar dilution, and the growth and survival analysis were also performed. LadR was expressed and the interaction between LadR and the mdrL promoter was investigated by electrophoretic mobility shift assay (EMSA). Compared to the wild-type strain, the growth of ΔmdrL deletion mutant strain was impaired in the presence of sublethal concentration of BC. Moreover, the mutant showed a lower level of survival than that of the wild-type strain in the presence of lethal concentration of BC. However, the deletion of mdrL had no impact on cefotaxime resistance and ethidium bromide efflux. BC could induce the expression of mdrL in L. monocytogenes and the mdrL expression was regulated by LadR instead of SigmaB. LadR was able to specifically bind to the mdrL promoter. The results showed that efflux pump MdrL was associated with BC tolerance in L. monocytogenes EGD-e. Moreover, our results also provided strong evidence that LadR negatively regulated the expression of mdrL. Since BC is commonly used in the food industry, efflux pump MdrL is beneficial for L. monocytogenes to survive this stress in food processing environments.
      PubDate: 2018-12-11
      DOI: 10.1007/s00253-018-9551-y
       
  • Cultivar and phosphorus effects on switchgrass yield and rhizosphere
           microbial diversity
    • Authors: Anne Sawyer; Christopher Staley; John Lamb; Craig Sheaffer; Thomas Kaiser; Jessica Gutknecht; Michael J. Sadowsky; Carl Rosen
      Abstract: Switchgrass (Panicum virgatum L.) is a native perennial grass identified as a promising biofuel crop for production on marginal agricultural lands. As such, research into switchgrass fertility and the switchgrass rhizosphere microbiome has been ongoing in an effort to increase production sustainability. We examined the effects of cultivar and phosphorus (P) fertilization on biomass yield, P removal, and rhizosphere bacterial and fungal community structure in three switchgrass cultivars: Sunburst, Shawnee, and Liberty. The Liberty cv. is the first lowland-type bioenergy switchgrass adapted to USDA hardiness zones 4, 5, and 6. On a medium soil test P clay loam soil, biomass yield response to applied P was linear, increasing 135 kg ha−1 for every kilogram of P applied prior to establishment. Average post-frost biomass yield was 9.6 Mg ha−1 year−1 when unfertilized, and maximum biomass yield was 10.3 Mg ha−1 year−1 when fertilized at 58.6 kg ha−1 P, suggesting that P application on medium soil test P soils is beneficial for switchgrass establishment and early growth. Switchgrass cv. Shawnee was more productive than cvs. Liberty or Sunburst (11.3, 10.2, and 8.6 Mg ha−1 year−1, respectively). Both bacterial and fungal communities were significantly shaped by cultivar. These shifts, while inconsistent between year and cultivar, may reflect a selection of the microbial community from that present in soil to maximize total nutrient uptake, regardless of additional P amendments. Phosphorus fertilization did not affect microbial community structure. Results of this study suggest that the cultivar-associated selection of particular microbial taxa may have implications for increased productivity.
      PubDate: 2018-12-07
      DOI: 10.1007/s00253-018-9535-y
       
  • Suhuai suckling piglet hindgut microbiome-metabolome responses to
           different dietary copper levels
    • Authors: Feng Zhang; Weijiang Zheng; Yongqiang Xue; Wen Yao
      Abstract: Unabsorbed copper accumulates in the hindgut of pigs that consume high levels of dietary copper, which enhances the coselection of antibiotic-resistant bacteria and is considered detrimental to the environment and to porcine health. In our study, a combination of 16S rRNA pyrosequencing and nontargeted metabolomics was used to investigate the microbiome-metabolome responses to dietary copper levels in the hindgut of suckling piglets. The results showed that the dietary copper level affected the abundance of several Clostridia genera and that the relative abundance of butyrate-producing bacteria, such as Coprococcus, Roseburia, and Acidaminococcus, was reduced in the 300 mg kg−1 (high) Cu group. Metabolomic analysis revealed that dietary copper levels affected protein and carbohydrate metabolites, protein biosynthesis, the urea cycle, galactose metabolism, gluconeogenesis, and amino acid metabolism (including the metabolism of arginine, proline, β-alanine, phenylalanine, tyrosine, and methionine). Furthermore, Pearson’s correlation analysis showed that the abundance levels of Coprococcus (family Lachnospiraceae) and operational taxonomic unit (OTU) 18 (family Ruminococcaceae) were positively correlated with energy metabolism pathways (gluconeogenesis, glycolysis, and the pentose phosphate pathway). The abundance of Streptococcus was negatively correlated with amino acid metabolism pathways (protein biosynthesis, glycine, serine, threonine, methionine, phenylalanine, and tyrosine metabolism), and OTU583 and OTU1067 (family Rikenellaceae) were positively correlated with amino acid metabolism pathways. These results suggest that the copper levels consumed by LC (low-copper group) versus HC (high-copper group) animals alter the composition of the gut microbiota and modulate microbial metabolic pathways, which may further affect the health of suckling piglets.
      PubDate: 2018-12-07
      DOI: 10.1007/s00253-018-9533-0
       
  • Heavy water-labeled Raman spectroscopy reveals
           carboxymethylcellulose-degrading bacteria and degradation activity at the
           single-cell level
    • Authors: Oladipo Oladiti Olaniyi; Kai Yang; Yong-Guan Zhu; Li Cui
      Abstract: Biodegradation of cellulose-rich substrates is an indispensable process for soil carbon replenishment in various ecological niches. Biodegradation of cellulose has been studied extensively via an enzyme assay to quantify the amount of cellulase with a view to identify effective cellulose degraders. However, a bulk enzyme assay undermines the role of physiological heterogeneity between cells; it is therefore imperative to opt out for a more effective method such as single-cell Raman spectroscopy combined with heavy water (D2O) to reveal active cellulose degraders. Cellular incorporation of D2O-derived D produces a new C-D Raman band which can act as a quantitative indicator of microbial activity. In this study, metabolic responses of seven cellulose-degrading bacteria to carboxymethylcellulose (CMC) and glucose were evaluated via the C-D Raman band. On the basis of % C-D, CMC was demonstrated to be most efficiently metabolized by Bacillus velezensis 2a-9 and Providencia vermicola 5a-9(b). Metabolic activity between individual cells of B. velezensis and P. vermicola towards CMC ranged from approximately 8 to 27% and 6 to 16%, respectively, clearly indicating heterogeneous degradation activities among isogenic populations. Linear correlation between % C-D and specific endoglucanase activity validated Raman results on CMC-degrading activity. Also, % C-D obtained from bacteria cultivated with only glucose was around 60% higher than that obtained from CMC, indicating the preference of bacteria for simple sugar glucose than CMC. In conclusion, Raman spectroscopy combined with heavy water is a sensitive analytical technique to reveal cellulose degraders and their degrading activities.
      PubDate: 2018-12-07
      DOI: 10.1007/s00253-018-9459-6
       
  • Reverse metabolic engineering in lager yeast: impact of the NADH/NAD +
           ratio on acetaldehyde production during the brewing process
    • Authors: Xin Xu; Jinjing Wang; Min Bao; Chengtuo Niu; Chunfeng Liu; Feiyun Zheng; Yongxian Li; Qi Li
      Abstract: Acetaldehyde is synthesized by yeast during the main fermentation period of beer production, which causes an unpleasant off-flavor. Therefore, there has been extensive effort toward reducing acetaldehyde to obtain a beer product with better flavor and anti-staling ability. In this study, we discovered that acetaldehyde production in beer brewing is closely related with the intracellular NADH equivalent regulated by the citric acid cycle. However, there was no significant relationship between acetaldehyde production and amino acid metabolism. A reverse engineering strategy to increase the intracellular NADH/NAD+ ratio reduced the final acetaldehyde production level, and vice versa. This work offers new insight into acetaldehyde metabolism and further provides efficient strategies for reducing acetaldehyde production by the regulating the intracellular NADH/NAD+ ratio through cofactor engineering.
      PubDate: 2018-12-07
      DOI: 10.1007/s00253-018-9517-0
       
  • Structure-based design of agarase AgWH50C from Agarivorans gilvus WH0801
           to enhance thermostability
    • Authors: Pujuan Zhang; Jinru Zhang; Lujia Zhang; Jianan Sun; Yuan Li; Lian Wu; Jiahai Zhou; Changhu Xue; Xiangzhao Mao
      Abstract: AgWH50C, an exo-β-agarase of GH50 isolated from Agarivorans gilvus WH0801, plays a key role in the enzymatic production of neoagarobiose, which has great application prospect in the cosmetics and pharmaceutical industry. In contrast, the poor thermostability becomes the main obstructive factor of glycoside hydrolase (GH) family 50 agarases, including AgWH50C. Herein, based on the AgWH50C crystal structure, we designed several mutants by a multiple cross-linked rational design protocol used thermostability predicting softwares ETSS, PoPMuSiC, and HotMuSiC. To our surprise, the mutant K621F increased its relative activity by as much as 45% and the optimal temperature increased to 38 °C compared to that of wild-type, AgWH50C (30 °C). The thermostability of K621F also exhibited a substantial improvement. Considering that the gelling temperature of the agarose is higher than 35 °C, K621F can be used to hydrolyze agarose for neoagarobiose production.
      PubDate: 2018-12-06
      DOI: 10.1007/s00253-018-9540-1
       
  • Biological synthesis of high-conductive pili in aerobic bacterium
           Pseudomonas aeruginosa
    • Authors: Xi Liu; Shiwei Wang; Anming Xu; Li Zhang; Hongsheng Liu; Luyan Z. Ma
      Abstract: Bioelectrical nanowires as ecomaterials have great potential on environmental applications. A wide range of bacteria can express type IV pili (T4P), which are long protein fibers assembled from PilA. The T4P of Geobacter sulfurreducens are well known as “microbial nanowires,” yet T4P of Pseudomonas aeruginosa (PaT4P) was believed to be poorly conductive. P. aeruginosa is an aerobic and electrochemically active bacterium. Its T4P have been known to be responsible for surface attachment, twitching motility and biofilm formation. Here, we show that PaT4P can be highly conductive while assembled by a truncated P. aeruginosa PilA (PaPilA) containing only N-terminus 61 amino acids. Furthermore, increasing the number of aromatic amino acids in the PaPilA1–61 significantly enhances the conductivity of pili and the bioelectricity output of P. aeruginosa in microbial fuel cell system, suggesting a potential application of PaT4P as a conductive nanomaterial. The N-terminal region of PilA from diverse eubacteria is highly conserved, implying a general way to synthesize highly conductive microbial nanowires and to increase the bioelectricity output of microbial fuel cell.
      PubDate: 2018-12-06
      DOI: 10.1007/s00253-018-9484-5
       
  • Selectable marker recycling in the nonconventional yeast Xanthophyllomyces
           dendrorhous by transient expression of Cre on a genetically unstable
           vector
    • Authors: Ning Zhang; Jiaxin Li; Fuli Li; Shi’an Wang
      Abstract: Selectable marker recycling is a basic technique in bioengineering. However, this technique is usually unavailable in non-model microorganisms. In this study, we proposed a simple and efficient method for selectable marker recycling in the astaxanthin-synthesizing yeast Xanthophyllomyces dendrorhous. This method was based on a Cre-loxP system, in which the transient expression of the Cre recombinase was controlled by a genetically unstable vector independent of episomal plasmids and inducible promoters. The selectable markers in single-gene locus and multigene loci were removed along with the loss of the Cre vector with a ratio of 100% and 29%, respectively. The significance of the method was highlighted by the finding that stable autotrophic mutants were not readily obtained in X. dendrorhous. Comparative studies in X. dendrorhous and the non-homologous end joining dominant yeast Yarrowia lipolytica suggested that the method could be universally used in homologous recombination dominant yeasts.
      PubDate: 2018-12-04
      DOI: 10.1007/s00253-018-9496-1
       
  • Study on expression and action mode of recombinant alginate lyases based
           on conserved domains reconstruction
    • Authors: Min Yang; Nannan Li; Suxiao Yang; Yuan Yu; Zhenlian Han; Li Li; Haijin Mou
      Abstract: Understanding the effect of conserved domains reconstruction of alginate lyases on action mode is essential for their application and in-depth study. We report the expression and action mode of recombinant alginate lyase (AlyM) and its conserved domain reconstruction forms (AlyMΔCBM, cAlyM, and AlyMΔ58C). The enzymatic activities of AlyM, AlyMΔCBM, cAlyM, and AlyMΔ58C were 61.77, 150.57, 388.97, and 308.21 U/mg, respectively. The transcription level of cAlyM was 49.89-fold of AlyM. cAlyM and AlyMΔ58C showed higher thermal stability than AlyM, indicating that the removal of F5_F8_type_C domain was beneficial for the increase of thermal stability. The enzymes were bifunctional alginate lyases and preferred polyG to polyM. The enzymes degraded alginate to produce unsaturated disaccharide, trisaccharide, and tetrasaccharide as the main end-products. Pentamannuronic acid and pentaguluronic acid were the smallest substrates that could be degraded by AlyM, with unsaturated trisaccharide/tetrasaccharide (40.61%/44.42%) and disaccharide/trisaccharide (10.57%/83.85%) as the main products, respectively. The action modes of enzymes remain unaffected after conserved domain reconstruction, but the affinity of AlyMΔ58C toward polyM increased. This study provides a new strategy for rational modification of alginate lyase based on conserved domain reconstruction.
      PubDate: 2018-12-04
      DOI: 10.1007/s00253-018-9502-7
       
  • Brewing with malted barley or raw barley: what makes the difference in the
           processes'
    • Authors: Yee Jiun Kok; Lijuan Ye; Jeroen Muller; Dave Siak-Wei Ow; Xuezhi Bi
      Abstract: Malted barley is the main source for fermentable sugars used by yeasts in the traditional brewing of beers but its use has been increasingly substituted by unmalted barley and other raw grain adjuncts in recent years. The incorporation of raw grains is mainly economically driven, with the added advantage of improved sustainability, by reducing reliance on the malting process and its associated cost. The use of raw grains however, especially in high proportion, requires modifications to the brewing process to accommodate the lack of malt enzymes and the differences in structural and chemical composition between malted and raw grains. This review describes the traditional malting and brewing processes for the production of full malt beer, compares the modifications to these processes, namely milling and mashing, when raw barley or other grains are used in the production of wort—a solution of fermentable extracts metabolized by yeast and converted into beer, and discusses the activity of endogenous malt enzymes and the use of commercial brewing enzyme cocktails which enable high adjunct brewing.
      PubDate: 2018-12-04
      DOI: 10.1007/s00253-018-9537-9
       
  • PHA synthase (PhaC): interpreting the functions of bioplastic-producing
           enzyme from a structural perspective
    • Authors: Min Fey Chek; Ayaka Hiroe; Toshio Hakoshima; Kumar Sudesh; Seiichi Taguchi
      Abstract: Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by a wide range of bacteria, which serve as a promising candidate in replacing some conventional petrochemical-based plastics. PHA synthase (PhaC) is the key enzyme in the polymerization of PHA, and the crystal structures were successfully determined using the catalytic domain of PhaC from Cupriavidus necator (PhaCCn-CAT) and Chromobacterium sp. USM2 (PhaCCs-CAT). Here, we review the beneficial mutations discovered in PhaCs from a structural perspective. The structural comparison of the residues involved in beneficial mutation reveals that the residues are near to the catalytic triad, but not inside the catalytic pocket. For instance, Ala510 of PhaCCn is near catalytic His508 and may be involved in the open-close regulation, which presumably play an important role in substrate specificity and activity. In the class II PhaC1 from Pseudomonas sp. 61-3 (PhaC1Ps), Ser325 stabilizes the catalytic cysteine through hydrogen bonding. Another residue, Gln508 of PhaC1Ps is located in a conserved hydrophobic pocket which is next to the catalytic Asp and His. A class I, II-conserved Phe420 of PhaCCn is one of the residues involved in dimerization and its mutation to serine greatly reduced the lag phase. The current structural analysis shows that the Phe362 and Phe518 of PhaC from Aeromonas caviae (PhaCAc) are assisting the dimer formation and maintaining the integrity of the core beta-sheet, respectively. The structure-function relationship of PhaCs discussed in this review will serve as valuable reference for future protein engineering works to enhance the performance of PhaCs and to produce novel biopolymers.
      PubDate: 2018-12-03
      DOI: 10.1007/s00253-018-9538-8
       
 
 
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