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BIOTECHNOLOGY (227 journals)                  1 2 | Last

Showing 1 - 200 of 227 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
Advances in Bioscience and Biotechnology     Open Access   (Followers: 15)
Advances in Genetic Engineering & Biotechnology     Hybrid Journal   (Followers: 8)
African Journal of Biotechnology     Open Access   (Followers: 6)
Algal Research     Partially Free   (Followers: 9)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 69)
American Journal of Bioinformatics Research     Open Access   (Followers: 8)
American Journal of Polymer Science     Open Access   (Followers: 30)
Animal Biotechnology     Hybrid Journal   (Followers: 10)
Annales des Sciences Agronomiques     Full-text available via subscription  
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 42)
Applied Bioenergy     Open Access  
Applied Biosafety     Hybrid Journal  
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 62)
Applied Mycology and Biotechnology     Full-text available via subscription   (Followers: 5)
Arthroplasty Today     Open Access   (Followers: 1)
Artificial Cells, Nanomedicine and Biotechnology     Hybrid Journal   (Followers: 2)
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: 4)
Bio-Algorithms and Med-Systems     Hybrid Journal   (Followers: 1)
Bio-Research     Full-text available via subscription   (Followers: 2)
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  
Biofuels     Hybrid Journal   (Followers: 11)
Biofuels Engineering     Open Access   (Followers: 1)
Biological & Pharmaceutical Bulletin     Full-text available via subscription   (Followers: 5)
Biological Cybernetics     Hybrid Journal   (Followers: 10)
Biomarkers and Genomic Medicine     Open Access   (Followers: 5)
Biomarkers in Drug Development     Partially Free   (Followers: 1)
Biomaterials Research     Open Access   (Followers: 4)
BioMed Research International     Open Access   (Followers: 6)
Biomédica     Open Access  
Biomedical Engineering Research     Open Access   (Followers: 7)
Biomedical glasses     Open Access  
Biomedical Reports     Full-text available via subscription  
BioMedicine     Open Access  
Bioprinting     Hybrid Journal  
Bioresource Technology Reports     Hybrid Journal  
Bioscience, Biotechnology, and Biochemistry     Hybrid Journal   (Followers: 22)
Biosimilars     Open Access   (Followers: 1)
Biosurface and Biotribology     Open Access  
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
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: 7)
Biotechnology & Biotechnological Equipment     Open Access   (Followers: 5)
Biotechnology Advances     Hybrid Journal   (Followers: 33)
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: 14)
Biotechnology and Health Sciences     Open Access   (Followers: 1)
Biotechnology and Molecular Biology Reviews     Open Access   (Followers: 1)
Biotechnology Annual Review     Full-text available via subscription   (Followers: 7)
Biotechnology for Biofuels     Open Access   (Followers: 11)
Biotechnology Frontier     Open Access   (Followers: 2)
Biotechnology Journal     Hybrid Journal   (Followers: 16)
Biotechnology Law Report     Hybrid Journal   (Followers: 4)
Biotechnology Letters     Hybrid Journal   (Followers: 34)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Biotechnology Reports     Open Access  
Biotechnology Research International     Open Access   (Followers: 2)
Biotechnology Techniques     Hybrid Journal   (Followers: 10)
Biotecnología Aplicada     Open Access  
Biotribology     Hybrid Journal  
BMC Biotechnology     Open Access   (Followers: 16)
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)
Contributions to Tobacco Research     Open Access   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Critical Reviews in Biotechnology     Hybrid Journal   (Followers: 20)
Crop Breeding and Applied Biotechnology     Open Access   (Followers: 4)
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: 14)
Current trends in Biotechnology and Pharmacy     Open Access   (Followers: 9)
EBioMedicine     Open Access  
Electronic Journal of Biotechnology     Open Access   (Followers: 1)
Entomologia Generalis     Full-text available via subscription  
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: 13)
Food Science and Biotechnology     Hybrid Journal   (Followers: 9)
Frontiers in Bioengineering and Biotechnology     Open Access   (Followers: 6)
Frontiers in Systems Biology     Open Access   (Followers: 2)
Fungal Biology and Biotechnology     Open Access   (Followers: 1)
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  
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)
IIOAB Letters     Open Access  
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: 1)
Indonesian Journal of Biotechnology     Open Access   (Followers: 1)
Industrial Biotechnology     Hybrid Journal   (Followers: 18)
International Biomechanics     Open Access  
International Journal of Bioinformatics Research and Applications     Hybrid Journal   (Followers: 15)
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: 2)
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)
Journal of Biometrics & Biostatistics     Open Access   (Followers: 3)
Journal of Bioterrorism & Biodefense     Open Access   (Followers: 6)
Journal of Petroleum & Environmental Biotechnology     Open Access   (Followers: 2)
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: 6)
Journal of Applied Biomedicine     Open Access   (Followers: 3)
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 Biosecurity, Biosafety and Biodefense Law     Hybrid Journal   (Followers: 3)
Journal of Biotechnology     Hybrid Journal   (Followers: 68)
Journal of Chemical and Biological Interfaces     Full-text available via subscription   (Followers: 1)
Journal of Chemical Technology & Biotechnology     Hybrid Journal   (Followers: 10)
Journal of Chitin and Chitosan Science     Full-text available via subscription  
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: 7)
Journal of Essential Oil Research     Hybrid Journal   (Followers: 3)
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: 16)
Journal of Integrative Bioinformatics     Open Access  
Journal of International Biotechnology Law     Hybrid Journal   (Followers: 3)
Journal of Medical Imaging and Health Informatics     Full-text available via subscription  
Journal of Molecular Microbiology and Biotechnology     Full-text available via subscription   (Followers: 14)
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: 2)
Journal of Organic and Biomolecular Simulations     Open Access  
Journal of Plant Biochemistry and Biotechnology     Hybrid Journal   (Followers: 6)
Journal of Science and Applications : Biomedicine     Open Access  
Journal of the Mechanical Behavior of Biomedical Materials     Hybrid Journal   (Followers: 11)
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: 5)
Messenger     Full-text available via subscription  
Metabolic Engineering Communications     Open Access   (Followers: 4)
Metalloproteinases In Medicine     Open Access  
Microalgae Biotechnology     Open Access   (Followers: 2)
Microbial Biotechnology     Open Access   (Followers: 9)
MicroMedicine     Open Access   (Followers: 3)
Molecular and Cellular Biomedical Sciences     Open Access  
Molecular Biotechnology     Hybrid Journal   (Followers: 16)
Molecular Genetics and Metabolism Reports     Open Access   (Followers: 3)
Nanobiomedicine     Open Access  
Nanobiotechnology     Hybrid Journal   (Followers: 3)
Nanomaterials and Nanotechnology     Open Access  
Nanomaterials and Tissue Regeneration     Open Access  
Nanomedicine and Nanobiology     Full-text available via subscription  
Nanomedicine Research Journal     Open Access  
Nanotechnology Reviews     Hybrid Journal   (Followers: 5)
Nature Biotechnology     Full-text available via subscription   (Followers: 521)
Network Modeling and Analysis in Health Informatics and Bioinformatics     Hybrid Journal   (Followers: 3)
New Biotechnology     Hybrid Journal   (Followers: 4)
Nigerian Journal of Biotechnology     Open Access  
Nova Biotechnologica et Chimica     Open Access  
NPG Asia Materials     Open Access  
npj Biofilms and Microbiomes     Open Access  
OA Biotechnology     Open Access  
Plant Biotechnology Journal     Open Access   (Followers: 10)
Plant Biotechnology Reports     Hybrid Journal   (Followers: 4)
Preparative Biochemistry and Biotechnology     Hybrid Journal   (Followers: 4)

        1 2 | Last

Journal Cover Electronic Journal of Biotechnology
  [SJR: 0.365]   [H-I: 36]   [1 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Print) 0717-3458
   Published by Elsevier Homepage  [3177 journals]
  • Pretentious genomic selection signatures in CYP19A1 gene associated with
           silent estrous behavior in water buffalo in Pakistan

    • Authors: Sana Imran; Javed Maryam; Asif Nadeem; Madiha Iqbal
      Pages: 35 - 40
      Abstract: Publication date: March 2018
      Source:Electronic Journal of Biotechnology, Volume 32
      Author(s): Sana Imran, Javed Maryam, Asif Nadeem, Madiha Iqbal
      Background Poor reproductive efficiency of river buffalos hampers the production capabilities of animals. Buffalos are mainly considered poor breeders owing to the constrained expression of estrus behavior. Failure to display heat signs is an indication of improper functionality of signaling peptides to trigger on a series of behavioral changes, which can be detectable by breeders for timely insemination of females. This might cause an animal to be a repeat breeder. Genomic variations underlying synthesis of signaling peptides can be a useful marker to select superior animals with better reproductive efficiency. In this context, the current study was designed to analyze the CYP19A1 gene in Nili-Ravi buffalo. Results A total of 97 animals were selected and were divided into two groups on the basis of their heat score. PCR amplification and sequencing of the amplicons were performed using the specific sets of primer, and then, sequences were analyzed for novel variants. A total of 11 polymorphic sites were identified illustrating phenotypic variation in the heat score. Most of the loci were found homologous. Single Nucleotide Polymorphisms (SNPs) were analyzed for association with silent estrus. A three-dimensional protein model was also generated to locate the position of exonic SNPs. Conclusion This study illustrated that polymorphic sites in the CYP19A1 gene provided potential markers for selection of buffalos with better estrus behavior.

      PubDate: 2018-02-17T05:33:24Z
      DOI: 10.1016/j.ejbt.2018.01.001
      Issue No: Vol. 32 (2018)
  • Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive
           compound through alteration of EPS and epiphytic bacteria

    • Authors: Claudia Infante; Francisca Castillo; Vilma Pérez; Carlos Riquelme
      Abstract: Publication date: Available online 14 March 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Claudia Infante, Francisca Castillo, Vilma Pérez, Carlos Riquelme
      Background Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS), suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.

      PubDate: 2018-03-19T10:26:12Z
      DOI: 10.1016/j.ejbt.2018.03.002
  • Increasing pinosylvin production in Escherichia coli by reducing the
           expression level of the gene fabI-encoded enoyl-acyl carrier protein

    • Authors: Caheri Salas-Navarrete; Georgina Hernández-Chávez; Noemí Flores; Luz María Martínez; Alfredo Martinez; Francisco Bolívar; Francisco Barona-Gomez; Guillermo Gosset
      Abstract: Publication date: Available online 8 March 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Caheri Salas-Navarrete, Georgina Hernández-Chávez, Noemí Flores, Luz María Martínez, Alfredo Martinez, Francisco Bolívar, Francisco Barona-Gomez, Guillermo Gosset
      Background The plant secondary metabolite pinosylvin is a polyphenol from the stilbene family, which have positive effects on human health. Biotechnological production is an attractive alternative for obtaining this stilbene. In Escherichia coli, malonyl-CoA is the precursor for both stilbene and fatty acid syntheses. In this study, with the aim of increasing pinosylvin production, we evaluated a novel approach that is based on reducing the expression of the gene fabI, which encodes the enzyme enoyl-acyl carrier protein reductase that is involved in fatty acid synthesis. Results A recombineering method was employed to eliminate the chromosomal -35 promoter sequence and the upstream region of the gene fabI in E. coli strain W3110. Analysis, employing RT-qPCR, showed that such modification caused a 60% reduction in the fabI transcript level in the mutant strain W3110Δ-35fabI::Cm compared to the wild type W3110. Synthetic genes encoding a mutant version of 4-coumaroyl-CoA ligase from Streptomyces coelicolor A3 with improved catalytic activity employing cinnamic acid as substrate and a stilbene synthase from Vitis vinifera were cloned to generate the plasmid pTrc-Sc4CL(M)-VvSTS. The production performance of strains W3110Δ-35fabI::Cm/pTrc-Sc4CL(M)-VvSTS and W3110/pTrc-Sc4CL(M)-VvSTS was determined in shake flask cultures with Luria-Bertani medium supplemented with 10g/L glycerol and 3mM cinnamic acid. Under these conditions, the strain W3110Δ-35fabI::Cm/pTrc-Sc4CL(M)-VvSTS produced 52.67mg/L pinosylvin, a level 1.5-fold higher than that observed with W3110/pTrc-Sc4CL(M)-VvSTS. Conclusion A reduction in the transcript level of fabI caused by the elimination of the -35 and upstream promoter sequences is a successful strategy to improve pinosylvin production in E. coli.

      PubDate: 2018-03-19T10:26:12Z
      DOI: 10.1016/j.ejbt.2018.03.001
  • Immunosuppressive mechanism of Hypoderma lineatum secreted serine
           esterase, a potential modulatory method used to inhibit transplant

    • Authors: Quangang Chen; Renjin Chen; Honghua Yuan; Peng Liu; Ankang Hu; Lianlian Wu; Jing Liu
      Abstract: Publication date: Available online 3 February 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Quangang Chen, Renjin Chen, Honghua Yuan, Peng Liu, Ankang Hu, Lianlian Wu, Jing Liu
      Background Although immunosuppressive therapies have made organ transplantation a common medical procedure worldwide, chronic toxicity has a major issue for long-term treatment. One method to improve therapies and methods is the application of immunomodulatory agents from parasites such as Hypoderma lineatum. Hypodermin A (HA) is a serine esterase secreted by the larvae of Hypoderma lineatum, several studies demonstrated its immunosuppressive mechanism in vitro, and recently we discovered that HA inhibits the expression of interferon (IFN)-γ and interleukin (IL)-2 and activates IL-10 expression. Therefore, we hypothesized that it might be a potential agent used to block allograft rejections. However, most studies of the immunosuppressive mechanisms associated with HA were undertaken at the cellular level. In order to augment these studies, we evaluated the immunosuppressive effects of HA in vivo using an HA transgenic mouse model. Result Our results revealed similar findings to those reported by in vitro studies, specifically that HA induced prostaglandin E2 expression, downregulated IFN-γ and IL-2 expression, and promoted IL-10 secretion via E-type prostanoid receptor 4. Additionally, we observed that HA overexpression inhibited lipopolysaccharide-induced TLR4 activation. These findings provide insight into a new potential agent capable of blocking graft rejection. Conclusion Our founding suggested that HA-related treatment could be a promising option to improve the viability of grafts in human.

      PubDate: 2018-02-17T05:33:24Z
      DOI: 10.1016/j.ejbt.2018.01.005
  • Molecular characterization and expression analysis of cathepsin C in
           Chinese giant salamander (Andrias davidianus) after Aeromonas hydrophila

    • Authors: Zisheng Wang; Panpan Hang; Qihuan Zhang; Qiaoqing Xu; Zhitao Qi
      Abstract: Publication date: Available online 2 February 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Zisheng Wang, Panpan Hang, Qihuan Zhang, Qiaoqing Xu, Zhitao Qi
      Background Cathepsin C (CTSC) (dipeptidyl peptidase I, DPPI), is a member of the papain superfamily of cysteine proteases and involves in a variety of host reactions. However, the information of CTST in Chinese giant salamander (Andrias davidianus), an amphibian species with important evolutionary position and economic values, remained unclear. Results The full-length salamander CTSC cDNA contained a 96bp of 5′-UTR, a 1392bp of ORF encoding 463 amino acids, and a 95bp of 3′-UTR. The salamander CTSC possessed several sequence features similar to other reported CTSCs such as a signal peptide, a propeptide and a mature peptide. The active site triad of Cys, His and Asn were also found existing in salamander CTSC. Salamander CTSC mRNA was constitutively expressed in all the examined tissues with significantly variant expression level. The highest expression of CTSC was in intestine, followed with stomach, spleen, lung and brain. Following Aeromonas hydrophila infection for 12h, salamander CTSC was significantly up-regulated in several tissues including lung, spleen, brain, kidney, heart, stomach and skin. Conclusion CTSC plays roles in the immune response to bacterial infection, which provided valuable information for further studying the functions of CTSC in salamander.

      PubDate: 2018-02-17T05:33:24Z
      DOI: 10.1016/j.ejbt.2018.01.002
  • Intereactions between doripenem and clavulanate — Application of minimal
           inhibitory concentration analysis and cytometry flow for bactericidal

    • Authors: Katarzyna Ciemniak; Judyta Cielecka-Piontek; Daria Szymanowska; Gabriela Wiergowska
      Abstract: Publication date: Available online 2 February 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Katarzyna Ciemniak, Judyta Cielecka-Piontek, Daria Szymanowska, Gabriela Wiergowska
      Background In view of the current low efficacy of bacterial infection treatment the common trend towards searching for antibiotic systems exhibiting synergistic action is well justified. Among carbapenem analogues a particularly interesting option is provided by combinations of clavulanic acid with meropenem, which have proven to be especially effective. Results Determination of the minimal inhibitory concentration (MIC) along with the method based on flow cytometry constitutes an important tool in the identification of bacterial sensitivity to active substances. Within this study the inhibitory effect of doripenem, clavulanic acid and the doripenem-clavulanate acid system was analyzed in relation to such bacteria as Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Clostridium butyricum and Clostridium pasteurianum, Acinetobacter baumannii, Enterobacter aerogenes. The lowest MIC, amounting to 0.03μg/mL, was observed for the doripenem-clavulanate acid system in the case of E. coli ATCC 25922. In turn, the lowest MIC for doripenem applied alone was recorded for K. pneumoniae ATCC 31488, for which it was 0.1μg/mL. The strain which proved to be most resistant both to doripenem and the doripenem-clavulanate acid system, was A. baumannii, with MIC of 32μg/mL (clinical isolate) and 16μg/mL (reference strain). Cytometric analysis for P. aeruginosa ATCC 27853 and S. aureus ATCC 25923 showed changes in cells following exposure to limiting concentrations of the active substance. Conclusions Analysis of MIC supplies important information concerning microbial sensitivity to active substances, mainly in terms of limiting concentrations causing mortality or vitality of the tested species, which is essential when selecting appropriate antibiotic therapy.

      PubDate: 2018-02-17T05:33:24Z
      DOI: 10.1016/j.ejbt.2018.01.003
  • Molecular cloning and biochemical characterization of an α-amylase family
           from Aspergillus niger

    • Authors: Junying Wang; Yu Li; Fuping Lu
      Abstract: Publication date: Available online 31 January 2018
      Source:Electronic Journal of Biotechnology
      Author(s): Junying Wang, Yu Li, Fuping Lu
      Background α-Amylase is widely used in the starch processing, food and paper industries, hydrolyzing starch, glycogen and other polysaccharides into glucose, maltose and oligosaccharides. An α-amylase gene family from Aspergillus niger CBS513.88 encode eight putative α-amylases. The differences and similarities, biochemical properties and functional diversity among these eight α-amylases remains unknown. Results The eight genes were cloned and expressed in Pichia pastoris GS115 by shaking-flask fermentation under the induction of methanol. The sequence alignment, biochemical characterizations and product analysis of starch hydrolysis by these α-amylases were investigated. It is found that the eight α-amylases belonged to three different groups with the typical structure of fungal α-amylase. They exhibited maximal activities at 30–40°C except AmyG and were all stable at acidic pH. Ca2+ and EDTA had no effects on the activities of α-amylases except AmyF and AmyH, indicating that the six amylases were Ca2+ independent. Two novel α-amylases of AmyE and AmyF were found. AmyE hydrolyzed starch into maltose, maltotriose and a small amount of glucose, while AmyF hydrolyzed starch into mainly glucose. The excellent physical and chemical properties inlcuding high acidic stability, Ca2+-independent and high maltotriose-forming capacity make AmyE suitable in food and sugar syrup industries. Conclusions This study illustrates that a gene family can encode multiple enzymes members having remarkable differences in biochemical properties. It provides not only new insights into evolution and functional divergence among different members of an α-amylase family, but the development of new enzymes for industrial application.

      PubDate: 2018-02-17T05:33:24Z
      DOI: 10.1016/j.ejbt.2018.01.004
  • Editorial

    • Authors: Andres F. Illanes
      Abstract: Publication date: November 2017
      Source:Electronic Journal of Biotechnology, Volume 30
      Author(s): Andres F. Illanes

      PubDate: 2017-11-20T03:37:53Z
      DOI: 10.1016/j.ejbt.2017.10.007
      Issue No: Vol. 30 (2017)
  • Enhanced apoptosis and inhibition of gastric cancer cell invasion
           following treatment with LDH@Au loaded Doxorubicin

    • Authors: Hu Zhao; Xueqin Zhang
      Abstract: Publication date: Available online 20 December 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Hu Zhao, Xueqin Zhang
      Background The suppression of cancer cell growth and invasion has become a challenging clinical issue. In this study, we used nanotechnology to create a new drug delivery system to enhance the efficacy of existing drugs. We developed layered double hydroxide by combing Au nanosol (LDH@Au) and characterized the compound to prove its function as a drug delivery agent. The anti-cancer drug Doxorubicin was loaded into the new drug carrier to assess its quality. We used a combination of apoptosis assays, cell cycle assays, tissue distribution studies, cell endocytosis, transwell invasion assays, and immunoblotting to evaluate the characteristics of LDH@Au as a drug delivery system. Results Our results show the LDH@Au-Dox treatment significantly increased cancer cell apoptosis and inhibited cell invasion compared to the control Dox group. Additionally, our data indicate LDH@Au-Dox has a better target efficiency at the tumor site and improved the following: cellular uptake, anti-angiogenesis action, changes in the cell cycle, and increased caspase pathway activation. Conclusions Our findings suggest the nano drug is a promising anti-cancer agent and has potential clinical applications.

      PubDate: 2017-12-21T19:48:04Z
      DOI: 10.1016/j.ejbt.2017.12.004
  • Fermentation optimization and enzyme characterization of a new
           ι-Carrageenase from Pseudoalteromonas carrageenovora ASY5

    • Authors: Qiong Xiao; Yanbing Zhu; Jiajia Li; Changzheng Wu; Hui Ni; Anfeng Xiao
      Abstract: Publication date: Available online 20 December 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Qiong Xiao, Yanbing Zhu, Jiajia Li, Changzheng Wu, Hui Ni, Anfeng Xiao
      Background A new ι-carrageenase-producing strain was screened from mangroves and authenticated as Pseudoalteromonas carrageenovora ASY5 in our laboratory. The potential application of this new strain was evaluated. Results Medium compositions and culturing conditions in shaking flask fermentation were firstly optimized by single-factor experiment. ι-Carrageenase activity increased from 0.34U/mL to 1.08U/mL after test optimization. Optimal fermentation conditions were 20°C, pH7.0, incubation time of 40h, 15g/L NaCl, 1.5% (w/v) yeast extract as nitrogen source, and 0.9% (w/v) ι-carrageenan as carbon source. Then, the crude ι-carrageenase was characterized. The optimum temperature and pH of the ι-carrageenase were 40°C and 8.0, respectively. The enzymatic activity at 35–40°C for 45min retained more than 40% of the maximum activity. Meanwhile, The ι-carrageenase was inhibited by the addition of 1mmol/L Cd2+ and Fe3+ but increased by the addition of 1mmol/L Ag+, Ba2+, Ca2+, Co2+, Mn2+, Zn2+, Fe2+, and Al3+. The structure of oligosaccharides derived from ι-carrageenan was detected using electrospray ionization mass spectrometry (ESI-MS). The ι-carrageenase degraded ι-carrageenan, yielding disaccharides and tetrasaccharides as main products. Conclusions The discovery and study of new ι-carrageenases are beneficial not only for the production of ι-carrageenan oligosaccharides but also for the further utilization in industrial production.

      PubDate: 2017-12-21T19:48:04Z
      DOI: 10.1016/j.ejbt.2017.12.005
  • Transcriptome profiling and digital gene expression analysis of genes
           associated with salinity resistance in peanut

    • Authors: Jiongming Sui; Pingping Jiang; Guilong Qin; Shupeng Gai; Dan Zhu; Lixian Qiao; Jingshan Wang
      Abstract: Publication date: Available online 10 December 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Jiongming Sui, Pingping Jiang, Guilong Qin, Shupeng Gai, Dan Zhu, Lixian Qiao, Jingshan Wang
      Background Soil salinity can significantly reduce crop production, but the molecular mechanism of salinity tolerance in peanut is poorly understood. A mutant (S1) with higher salinity resistance than its mutagenic parent HY22 (S3) was obtained. Transcriptome sequencing and digital gene expression (DGE) analysis were performed with leaves of S1 and S3 before and after plants were irrigated with 250mM NaCl. Results A total of 107,725 comprehensive transcripts were assembled into 67,738 unigenes using TIGR Gene Indices clustering tools (TGICL). All unigenes were searched against the euKaryotic Ortholog Groups (KOG), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and these unigenes were assigned to 26 functional KOG categories, 56 GO terms, 32 KEGG groups, respectively. In total 112 differentially expressed genes (DEGs) between S1 and S3 after salinity stress were screened, among them, 86 were responsive to salinity stress in S1 and/or S3. These 86 DEGs included genes that encoded the following kinds of proteins that are known to be involved in resistance to salinity stress: late embryogenesis abundant proteins (LEAs), major intrinsic proteins (MIPs) or aquaporins, metallothioneins (MTs), lipid transfer protein (LTP), calcineurin B-like protein- interacting protein kinases (CIPKs), 9-cis-epoxycarotenoid dioxygenase (NCED) and oleosins, etc. Of these 86 DEGs, 18 could not be matched with known proteins. Conclusion The results from this study will be useful for further research on the mechanism of salinity resistance and will provide a useful gene resource for the variety breeding of salinity resistance in peanut.

      PubDate: 2017-12-11T10:08:31Z
      DOI: 10.1016/j.ejbt.2017.12.002
  • Cloning and heterologous expression of a hydrophobin gene Ltr.hyd from the
           tiger milk mushroom Lentinus tuber-regium in yeast-like cells of Tremella

    • Authors: Dongmei Liu; Hanyu Zhu; Yue Chen; Liesheng Zheng; Liguo Chen; Aimin Ma
      Abstract: Publication date: Available online 10 December 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Dongmei Liu, Hanyu Zhu, Yue Chen, Liesheng Zheng, Liguo Chen, Aimin Ma
      Background Hydrophobins are small proteins secreted by filamentous fungi, which show a highly surface activity. Because of the signally self-assembling abilities and surface activities, hydrophobins were considered as candidates in many aspects, for example, stabilizing foams and emulsions in food products. Lentinus tuber-regium, known as tiger milk mushroom, is both an edible and medicinal sclerotium-producing mushroom. Up to now, the hydrophobins of L. tuber-regium have not been identified. Results In this paper, a Class I hydrophobin gene, Ltr.hyd, was cloned from L. tuber-regium and expressed in the yeast-like cells of Tremella fuciformis mediated by Agrobacterium tumefaciens. The expression vector pGEH-GH was under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter. The integration of Ltr.hyd into the genome of T. fuciformis was confirmed by PCR, Southern blot, fluorescence observation and quantitative real-time PCR (qRT-PCR). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that recombinant hydrophobin rLtr.HYD with an expected molecular mass of 13 kDa was extracted. The yield of rLtr.HYD was 0.66 mg/g dry weight. The emulsifying activity of rLtr.HYD was better than the typical food emulsifiers sodium caseinate and Tween 20. Conclusions We evaluated the emulsifying property of hydrophobin Ltr.HYD, which can be potentially used as a food emulsifier.

      PubDate: 2017-12-11T10:08:31Z
      DOI: 10.1016/j.ejbt.2017.12.003
  • Development and characterization of polyclonal antibodies against the
           linker region of the telomere-binding protein TRF2

    • Authors: Nadya V. Ilicheva; Aleksandra O. Travina; Alexey P. Voronin; Olga I. Podgornaya
      Abstract: Publication date: Available online 7 December 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Nadya V. Ilicheva, Aleksandra O. Travina, Alexey P. Voronin, Olga I. Podgornaya
      Background TRF2 (telomeric repeat binding factor 2) is an essential component of the telomere-binding protein complex shelterin. TRF2 induces the formation of a special structure of telomeric DNA and counteracts activation of DNA damage-response pathways telomeres. TRF2 has a poorly characterized linker region (udTRF2) between its homodimerization and DNA-binding domains. Some lines of evidence have shown that this region could be involved in TRF2 interaction with nuclear lamina. Results In this study, the fragment of the TERF2 gene encoding udTRF2 domain of telomere-binding protein TRF2 was produced by PCR and cloned into the pET32a vector. The resulting plasmid pET32a-udTRF2 was used for the expression of the recombinant udTRF2 in E. coli RosettaBlue (DE3). The protein was isolated and purified using ammonium sulfate precipitation followed by ion-exchange chromatography. The purified recombinant protein udTRF2 was injected into guinea pigs to generate polyclonal antibodies. The ability of anti-udTRF2 antibodies to bind endogenous TRF2 in human skin fibroblasts was tested by western blotting and immunofluorescent staining. Conclusions In this study, the recombinant protein udTRF2 and antibodies to it were generated. Both protein and antibodies will provide a useful tool for investigation of the functions of the udTRF2 domain and its role in the interaction between TRF2 and nuclear lamina.

      PubDate: 2017-12-11T10:08:31Z
      DOI: 10.1016/j.ejbt.2017.12.001
  • Encapsulation of specific Salmonella Enteritidis phage f3αSE on
           alginate-spheres as a method for protection and dosification

    • Authors: María José Soto; Julio Retamales; Humberto Palza; Roberto Bastías
      Abstract: Publication date: Available online 24 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): María José Soto, Julio Retamales, Humberto Palza, Roberto Bastías
      Background Bacteriophages have been proposed as an alternative to control pathogenic bacteria resistant to antibiotics. However, they are not extensively used due to different factors such as vulnerability under environmental conditions and the lack of efficient administration methods. A potential solution is the encapsulation of bacteriophages in hydrogel polymers to increase their viability and as a controlled release method. This work describes the use of alginate-Ca+2 matrixes as mechanisms for protection and dosification of the phage f3αSE which has been successfully used to prevent infections produced by Salmonella Enteritidis. Results The viability of the pure phage is reduced in near 100% after 1-h incubation at pH2 or 3. However, the encapsulated phage remains active in 80, 6% at pH3, while no differences were observed at pH2, 4 or 7. Exposition of f3αSE to different T° showed that the viability of this phage decreased with increased T° to near 15% at 60°C, while the encapsulated phage remains with 50% viability at same temperature. Finally, the encapsulation of phages showed to extend their presence for 100h in the medium compared to non-encapsulated phages in a water flow system, which simulate automatic birdbath used in poultry industry, maintaining the phage concentration between 102 and 104 PFU/mL during 250h. Conclusions Encapsulation in alginate-Ca+2 spheres can be a good alternative to extend viability of phages and can be used as a phage method dosification method in water flow systems.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.006
  • Microbial mat ecosystems: Structure types, functional diversity, and
           biotechnological application

    • Authors: Cristina M. Prieto-Barajas; Eduardo Valencia-Cantero; Gustavo Santoyo
      Abstract: Publication date: Available online 21 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Cristina M. Prieto-Barajas, Eduardo Valencia-Cantero, Gustavo Santoyo
      Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.001
  • Expression profiles of five FT-like genes and functional analysis of
           PhFT-1 in a Phalaenopsis hybrid

    • Authors: Shushan Zhou; Li Jiang; Shuangxue Guan; Yongxia Gao; Qinghua Gao; Guangdong Wang; Ke Duan
      Abstract: Publication date: Available online 21 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Shushan Zhou, Li Jiang, Shuangxue Guan, Yongxia Gao, Qinghua Gao, Guangdong Wang, Ke Duan
      Background Phalaenopsis is an important ornamental flowering plant that belongs to the Orchidaceae family and is cultivated worldwide. Phalaenopsis has a long juvenile phase (about 18months); therefore, it is important to understand the genetic elements regulating the transition from vegetative phase to reproductive phase. In this study, FLOWERING LOCUS T (FT) homologs in Phalaenopsis were cloned, and their effects on flowering were analyzed. Results A total of five FT-like genes were identified in Phalaenopsis. Phylogenetic and expression analyses of these five FT-like genes indicated that some of these genes might participate in the regulation of flowering. A novel FT-like gene, PhFT-1, distantly related to previously reported FT genes in Arabidopsis and other dicot crops, was also found to be a positive regulator of flowering as heterologous expression of PhFT-1 in Arabidopsis causes an early flowering phenotype. Conclusions Five FT homologous genes from Phalaenopsis orchid were identified, and PhFT-1 positively regulates flowering.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.003
  • Production of thermostable β-glucosidase and CMCase by Penicillium sp.
           LMI01 isolated from the Amazon region

    • Authors: Pamella S. Santa-Rosa; Anita L. Souza; Rosemary A. Roque; Edmar V. Andrade; Spartaco Astolfi-Filho; Adolfo J. Mota; Carlos G. Nunes-Silva
      Abstract: Publication date: Available online 21 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Pamella S. Santa-Rosa, Anita L. Souza, Rosemary A. Roque, Edmar V. Andrade, Spartaco Astolfi-Filho, Adolfo J. Mota, Carlos G. Nunes-Silva
      Background Cellulolytic enzymes of microbial origin have great industrial importance because of their wide application in various industrial sectors. Fungi are considered the most efficient producers of these enzymes. Bioprospecting survey to identify fungal sources of biomass-hydrolyzing enzymes from a high-diversity environment is an important approach to discover interesting strains for bioprocess uses. In this study, we evaluated the production of endoglucanase (CMCase) and β-glucosidase, enzymes from the lignocellulolytic complex, produced by a native fungus. Penicillium sp. LMI01 was isolated from decaying plant material in the Amazon region, and its performance was compared with that of the standard isolate Trichoderma reesei QM9414 under submerged fermentation conditions. Results The effectiveness of LMI01 was similar to that of QM9414 in volumetric enzyme activity (U/mL); however, the specific enzyme activity (U/mg) of the former was higher, corresponding to 24.170U/mg of CMCase and 1.345U/mg of β-glucosidase. The enzymes produced by LMI01 had the following physicochemical properties: CMCase activity was optimal at pH4.2 and the β-glucosidase activity was optimal at pH6.0. Both CMCase and β-glucosidase had an optimum temperature at 60°C and were thermostable between 50 and 60°C. The electrophoretic profile of the proteins secreted by LMI01 indicated that this isolate produced at least two enzymes with CMCase activity, with approximate molecular masses of 50 and 35kDa, and β-glucosidases with molecular masses between 70 and 100kDa. Conclusions The effectiveness and characteristics of these enzymes indicate that LMI01 can be an alternative for the hydrolysis of lignocellulosic materials and should be tested in commercial formulations.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.005
  • Effect of ultraviolet radiation on physiological and biochemical
           properties of yeast Saccharomyces cerevisiae during fermentation of
           ultradispersed starch raw material

    • Authors: Victor Revin; Nelli Atykyan; Ekaterina Lyovina; Yuliya Dragunova; Victoriya Ushkina
      Abstract: Publication date: Available online 21 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Victor Revin, Nelli Atykyan, Ekaterina Lyovina, Yuliya Dragunova, Victoriya Ushkina
      Background Study of correlation between pretreatment of yeast with ultraviolet radiation and efficiency of further fermentation of wort made of ultrafine grain particles to ethanol. Results We investigated three races of industrial yeast Saccharomyces cerevisiae (native and irradiated by ultraviolet). Physiological properties during fermentation of starchy wort were tested in all variants. It was shown that activation of the yeast by ultraviolet radiation allows to further increase the ethanol yield by 25% on average compared with the native yeast races when using thin (up to micro- and nano-sized particles) or standard grain grinding. Conclusions Using mechanical two-stage grinding of starchy raw materials and ultraviolet pretreatment of yeast, the efficiency of saccharification of starch and fermentation of wort to ethanol was increased.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.004
  • Development and characterization of InDel markers for Lupinus luteus L.
           (Fabaceae) and cross-species amplification in other Lupin species

    • Authors: Claudia E. Osorio; Joshua A. Udall; Haroldo Salvo-Garrido; Iván J. Maureira-Butler
      Abstract: Publication date: Available online 17 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Claudia E. Osorio, Joshua A. Udall, Haroldo Salvo-Garrido, Iván J. Maureira-Butler
      Background Strong artificial selection and/or natural bottle necks may limit genetic variation in domesticated species. Lupinus luteus, an orphan temperate crop, has suffered diversity reductions during its bitter/sweet alkaloid domestication history, limiting breeding efforts and making molecular marker development a difficult task. The main goal of this research was to generate new polymorphic insertion–deletion (InDel) markers to aid yellow lupin genetics and breeding. By combining genomic reduction libraries and next generation sequencing, several polymorphic InDel markers were developed for L. luteus L. Results A total of 118 InDel in silico polymorphic markers were identified. Eighteen InDel primer sets were evaluated in a diverse L. luteus core collection, where amplified between 2–3 alleles per locus. Observed heterozygosity (HO; 0.0648 to 0.5564) and polymorphic information content (PIC; 0.06 to 0.48) estimations revealed a moderate level of genetic variation across L. luteus accessions. In addition, ten and nine InDel loci amplified successfully Lupinus hispanicus Boiss & Reut, and Lupinus mutabilis Sweet, respectively, two L. luteus close relatives. PCA analysis identified two L. luteus clusters, most likely explained by the domestication species history. Conclusion The development of InDel markers will facilitate the study of genetic diversity across L. luteus populations, as well as among closely related species.

      PubDate: 2017-12-01T06:49:16Z
      DOI: 10.1016/j.ejbt.2017.11.002
  • Chemical pretreatment of Arundo donax L. for second-generation ethanol

    • Authors: Juliana Silva Lemões; Claudia Fernanda Lemons e Silva; Sabrina Peres Farias Avila; Cândida Raquel Scherrer Montero; Sérgio Delmar dos Anjos e Silva; Dimitrios Samios; Maria do Carmo Ruaro Peralba
      Abstract: Publication date: Available online 3 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Juliana Silva Lemões, Claudia Fernanda Lemons e Silva, Sabrina Peres Farias Avila, Cândida Raquel Scherrer Montero, Sérgio Delmar dos Anjos e Silva, Dimitrios Samios, Maria do Carmo Ruaro Peralba
      Background Pretreatment of lignocellulosic biomass is essential for using it as a raw material for chemical and biofuel production. This study evaluates the effects of variables in the chemical pretreatment of the Arundo biomass on the glucose and xylose concentrations in the final enzymatic hydrolysate. Three pretreatments were tested: acid pretreatment, acid pretreatment followed by alkaline pretreatment, and alkaline pretreatment. Results The amounts of glucose and xylose released by the enzymatic hydrolysis of the Arundo biomass obtained from acid pretreatment ranged from 6.2 to 19.1g/L and 1.8 to 3.1g/L, respectively. The addition of alkaline pretreatment led to a higher yield from the enzymatic hydrolysis, with the average glucose concentration 3.5 times that obtained after biomass hydrolysis with an acid pretreatment exclusively. The use of an alkaline pretreatment alone resulted in glucose and xylose concentrations similar to those obtained in the two-step pretreatment: acid pretreatment followed by alkaline pretreatment. There was no significant difference in 5-hydroxymethylfurfural, furfural, or acetic acid concentrations among the pretreatments. Conclusion Alkaline pretreatment was essential for obtaining high concentrations of glucose and xylose. The application of an alkaline pretreatment alone resulted in high glucose and xylose concentrations. This result is very significant as it allows a cost reduction by eliminating one step.

      PubDate: 2017-11-20T03:37:53Z
      DOI: 10.1016/j.ejbt.2017.10.011
  • Bioelectrogenesis with microbial fuel cells (MFCs) using the microalga
           Chlorella vulgaris and bacterial communities

    • Authors: Ronald Huarachi-Olivera; Alex Dueñas-Gonza; Ursulo Yapo-Pari; Patricia Vega; Margiht Romero-Ugarte; Juan Tapia; Luis Molina; Antonio Lazarte-Rivera; David G. Pacheco-Salazar; Mario Esparza-Mantilla
      Abstract: Publication date: Available online 9 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Ronald Huarachi-Olivera, Alex Dueñas-Gonza, Ursulo Yapo-Pari, Patricia Vega, Margiht Romero-Ugarte, Juan Tapia, Luis Molina, Antonio Lazarte-Rivera, David G. Pacheco-Salazar, Mario Esparza-Mantilla
      Background Microbial Fuel Cell (MFC) technology is used in various applications such as wastewater treatment with the production of electrical energy. The objective of this study was to estimate the biodepuration of oils and fats, the elimination of blue dye brl and bioelectro-characterization in MFCs with Chlorella vulgaris and bacterial community. Results The operation of MFCs at 32d showed an increase in bioelectrogenic activity (from 23.17 to 327.67mW/m2) and in the potential (from 200 to 954mV), with biodepuration of fats and oils (95%) in the microalgal cathode, and a removal of the chemical oxygen demand COD (anode, 71%, cathode, 78.6%) and the blue dye brl (73%) at the anode, here biofilms were formed by the bacterial community consisting of Actinobacteria and Deltaproteobacteria. Conclusions These findings suggest that MFCs with C. vulgaris and bacterial community have a simultaneous efficiency in the production of bioelectricity and bioremediation processes, becoming an important source of bioenergy in the future.

      PubDate: 2017-11-12T02:08:53Z
      DOI: 10.1016/j.ejbt.2017.10.013
  • Bacteriophages in the control of pathogenic vibrios

    • Authors: Nicolás Plaza; Daniel Castillo; Diliana Pérez-Reytor; Gastón Higuera; Katherine García; Roberto Bastías
      Abstract: Publication date: Available online 7 November 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Nicolás Plaza, Daniel Castillo, Diliana Pérez-Reytor, Gastón Higuera, Katherine García, Roberto Bastías
      Vibrios are common inhabitants of marine and estuarine environments. Some of them can be pathogenic to humans and/or marine animals using a broad repertory of virulence factors. Lately, several reports have indicated that the incidence of Vibrio infections in humans is rising and also in animals constitute a continuing threat for aquaculture. Moreover, the continuous use of antibiotics has been accompanied by an emergence of antibiotic resistance in Vibrio species, implying a necessity for efficient treatments. One promising alternative that emerges is the use of lytic bacteriophages; however, there are some drawbacks that should be overcome to make phage therapy a widely accepted method. In this work, we discuss about the major pathogenic Vibrio species and the progress, benefits and disadvantages that have been detected during the experimental use of bacteriophages to their control.

      PubDate: 2017-11-12T02:08:53Z
      DOI: 10.1016/j.ejbt.2017.10.012
  • Overexpression of CDC25C affects the cell cycle of ovarian granulosa cells
           from adult and young goats

    • Authors: Haiyan Guo; Qiang Wang; Yongjun Li; Xiuyuan Yin; Hao Zhang; Jianfei Shi
      Abstract: Publication date: Available online 29 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Haiyan Guo, Qiang Wang, Yongjun Li, Xiuyuan Yin, Hao Zhang, Jianfei Shi
      Background CDC25 is a dual-specificity phosphatase that was first identified in the yeast Schizosaccharomyces pombe as a cell cycle-defective mutant. Although CDC25 is involved in the cell cycle of ovarian granulosa cells, the CDC25 signaling pathway has not been clarified fully. To explore the role of CDC25C in the cell cycle of goat ovarian granulosa cells, a CDC25C-overexpressing vector, pCMV-HA-CDC25C, was constructed and transfected into granulosa cells from adult and young white goats from Jiangsu Nantong. RT-PCR was used to measure CDC25C, CDK1, and WEE1 gene expression levels, and flow cytometry was used to distinguish ovarian granulosa cells in different phases of the cell cycle. Progesterone and estradiol levels in transfected ovarian granulosa cells were also measured. Results In adult goat follicular granulosa cells transfected with pCMV-HA-CDC25C, CDC25C expression increased significantly, which greatly increased the relative gene expression levels of both CDK1 and WEE1. Additionally, progesterone and estradiol levels were increased in goat follicular granulosa cells overexpressing CDC25C. And the cell cycle results showed that transfection of pCMV-HA-CDC25C leads to a higher proportion of cells in S phase compared to the no vector-transfected groups. Conclusions The results of this study indicated that the overexpression of CDC25C may increase the gene expression levels of both WEE1 and CDK1 in S phase and accelerate the transition of cells from G1 phase to S phase.

      PubDate: 2017-11-04T22:24:34Z
      DOI: 10.1016/j.ejbt.2017.10.008
  • Characterization of the ligand binding of PGRP-L in half-smooth tongue
           sole (Cynogolossu semilaevis) by molecular dynamics and free energy

    • Authors: Zisheng Wang; Qihuan Zhang; Fancui Meng; Shuai Li; Qiaoqin Xu; Zhitao Qi
      Abstract: Publication date: Available online 29 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Zisheng Wang, Qihuan Zhang, Fancui Meng, Shuai Li, Qiaoqin Xu, Zhitao Qi
      Background Peptidoglycan (PGN) recognition proteins (PGRPs) are important pattern recognition receptors of host innate immune system, involving in the immune defense against bacterial pathogens. PGRPs have been characterized in several fish species. The PGN binding ability are important for the functions of PGRPs. However, the PGRP-PGN interaction mechanism in fish remained unclear. In the present study, the 3-D model of a long PGRP of half-smooth tongue sole (Cynogolossu semilaevis) (csPGRP-L), a marine teleost with great economic values, was constructed by comparative modeling method and the key amino acids involved in the interaction with Lys-type PGNs and Dap-type PGNs were analyzed by molecular dynamics and molecular docking methods. Results csPGRP-L possessed a typical PGRPs structure, consisting of five β-sheets and four α-helices. Molecular docking showed that the van der Waals provided slightly larger contribution than Coulombic interaction in the csPGRP-L-PGN complex. Further, binding energies of csPGRP-L-PGNs computed by MM-PBSA method revealed that csPGRP-L might selectively bind both types of MTP-PGNs and MPP-PGNs. In addition, the binding energy of each residue of csPGRP-L were also calculated, revealing the residues involved in the interaction with Lys-type PGNs were different from that of Dap-type PGNs. Conclusions The 3-D structure of csPGRP-L possessed typical PGRPs structure and might selectively bind both types of MTP- and MPP-PGNs, which provided useful insights to understand the functions of fish PGRPs.

      PubDate: 2017-11-04T22:24:34Z
      DOI: 10.1016/j.ejbt.2017.10.010
  • A novel chlorpyrifos hydrolase CPD from Paracoccus sp. TRP: Molecular
           cloning, characterization and catalytic mechanism

    • Authors: Shuanghu Fan; Kang Li; Yanchun Yan; Junhuan Wang; Jiayi Wang; Cheng Qiao; Ting Yang; Yang Jia; Baisuo Zhao
      Abstract: Publication date: Available online 27 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Shuanghu Fan, Kang Li, Yanchun Yan, Junhuan Wang, Jiayi Wang, Cheng Qiao, Ting Yang, Yang Jia, Baisuo Zhao
      Background Biodegradation is a reliable approach for efficiently eliminating persistent pollutants such as chlorpyrifos. Despite of many bacteria or fungi isolated from contaminate environment and capable of degrading chlorpyrifos, limited enzymes responsible for its degradation have been identified, let alone the catalytic mechanism of the enzymes. Results In present study, the gene cpd encoding a chlorpyrifos hydrolase was cloned by analysis of genomic sequence of Paracoccus sp. TRP. Phylogenetic analysis and BLAST indicated that CPD was a novel esterase of organophosphate hydrolases. The purified CPD enzyme, with conserved catalytic triad (Ser155-Asp251-His281) and motif Gly-Asp-Ser-Ala-Gly, was significantly inhibited by PMSF, a serine modifier. Molecular docking between CPD and chlorpyrifos showed that Ser155 was adjacent to chlorpyrifos, which indicated that Ser155 may be the active amino acid involved in chlorpyrifos degradation. This speculation was confirmed by site-directed mutagenesis of Ser155Ala accounting for the decreased activity of CPD towards chlorpyrifos. According to the key role of Ser155 in chlorpyrifos and molecular docking conformation, the nucleophilic catalytic mechanism for chlorpyrifos degradation by CPD was proposed. Conclusion The novel enzyme CPD was capable of hydrolyze chlorpyrifos and Ser155 played key role during degradation of chlorpyrifos.

      PubDate: 2017-10-28T19:52:27Z
      DOI: 10.1016/j.ejbt.2017.10.009
  • RecET recombination system driving chromosomal target gene replacement in
           Zymomonas mobilis

    • Authors: Yan Wu; Tao Li; Qinghua Cao; Xuedan Li; Yizheng Zhang; Xuemei Tan
      Abstract: Publication date: Available online 18 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Yan Wu, Tao Li, Qinghua Cao, Xuedan Li, Yizheng Zhang, Xuemei Tan
      Background Zymomonas mobilis is a Gram-negative microaerophilic bacterium with excellent ethanol-producing capabilities. The RecET recombination system provides an efficient tool for direct targeting of genes in the bacterial chromosome by PCR fragments. Results The plasmids pSUZM2a-RecET and pSUZM2a-RecE588T were first developed to co-express RecE or RecE588 and RecT for homologous recombination. Thereafter, the PCR fragments of the tetracycline resistance marker gene flanked by 60bp of adhA (alcohol dehydrogenase I) or adhB (alcohol dehydrogenase II) homologous sequences were electroporated directly into ZM4 cells harboring pSUZM2a-RecET or pSUZM2a-RecE588T. Both adhA and adhB were replaced by the tetracycline resistance gene in ZM4, yielding two mutant strains, Z. mobilis ZM4 ΔadhA and Z. mobilis ZM4 ΔadhB. These two mutants showed varying extent of reduction in ethanol production, biomass generation, and glucose metabolism. Furthermore, enzyme activity of alcohol dehydrogenase II in Z. mobilis ZM4 ΔadhB exhibited a significant reduction compared to that of wild-type ZM4. Conclusion This approach provided a simple and useful method for introducing mutations and heterologous genes in the Z. mobilis genome.

      PubDate: 2017-10-21T17:30:04Z
      DOI: 10.1016/j.ejbt.2017.10.005
  • A fast and efficient protocol for small RNA extraction in Japanese plum
           and other Prunus species

    • Authors: Evelyn Sánchez; David Tricon; Roxana Mora; Daniela Quiroz; Véronique Decroocq; Humberto Prieto
      Abstract: Publication date: Available online 17 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Evelyn Sánchez, David Tricon, Roxana Mora, Daniela Quiroz, Véronique Decroocq, Humberto Prieto
      Background Small ribonucleic acids represent an important repertoire of mobile molecules that exert key roles in several cell processes including antiviral defense. Small RNA based repertoire includes both small interfering RNA (siRNA) and microRNA (miRNA) molecules. In the Prunus genus, sharka disease, caused by the Plum pox virus (PPV), first occurred on European plum (Prunus domestica) and then spread over among all species in this genus and thus classified as quarantine pathogen. Next-generation sequencing (NGS) was used for the study of siRNA/miRNA molecules; however, NGS relies on adequate extraction protocols. Currently, knowledge of PPV-Prunus interactions in terms of siRNA populations and miRNA species is still scarce, and siRNA/miRNA extraction protocols are limited to species such as peach, almond, and sweet cherry. Results We describe a reliable procedure for siRNA/miRNA purification from Prunus salicina trees, in which previously used protocols did not allow adequate purification. The procedure was based on a combination of commercially available RNA purification kits and specific steps that yielded high quality purifications. The resulting molecules were adequate for library construction and NGS, leading to the development of a pipeline for analysis of both siRNAs and miRNAs in the PPV–P. salicina interactions. Results showed that PPV infection led to altered siRNA profiles in Japanese plum as characterized by decreased 24-nt and increased 21- and 22-nt siRNAs. Infections showed miR164 and miR160 generation and increased miR166, miR171, miR168, miR319, miR157, and miR159. Conclusion We propose this protocol as a reliable and reproducible small RNA isolation procedure for P. salicina and other Prunus species.

      PubDate: 2017-10-21T17:30:04Z
      DOI: 10.1016/j.ejbt.2017.10.006
  • Enhanced alkaline catalase production by Serratia marcescens FZSF01:
           enzyme purification, characterization, and recombinant expression

    • Authors: Xianbo Jia; Xinjian Lin; Chenqiang Lin; Lirong Lin; Jichen Chen
      Abstract: Publication date: Available online 13 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Xianbo Jia, Xinjian Lin, Chenqiang Lin, Lirong Lin, Jichen Chen
      Background Catalase (CAT) is an important enzyme that degrades H2O2 into H2O and O2. To obtain an efficient catalase, in this study, a new strain of high catalase-producing Serratia marcescens, named FZSF01, was screened and its catalase was purified and characterized. Results After optimization of fermentation conditions, the yield of catalase produced by this strain was as high as 51,468 U/ml. This catalase was further purified using two steps: DEAE-fast flow and Sephedex-G150. The purified catalase showed a specific activity of 197,575 U/mg with a molecular mass of 58 kDa. This catalase exhibited high activity at 20°C~70°C and pH 5.0~11.0. Km of the catalase was approximately 68 mM, and Vmax was 1886.8 mol/min mg. This catalase was further identified by LC-MS/MS, and the encoding gene was cloned and expressed in Escherichia coli BL21 (DE3) with a production of 17,267 ± 2037 U/ml. Conclusions To our knowledge, these results represent one of the highest fermentation levels reported among current catalase-producing strains. This FZSF01 catalase may be suitable for several industrial applications that comprise exposure to alkaline conditions and under a wide range of temperatures.

      PubDate: 2017-10-15T16:59:10Z
      DOI: 10.1016/j.ejbt.2017.10.001
  • Development of a novel vector for cloning and expressing extremely toxic
           genes in Escherichia coli

    • Authors: Hedan Li; Chengwei Hao; Daqing Xu
      Abstract: Publication date: Available online 10 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Hedan Li, Chengwei Hao, Daqing Xu
      Background Escherichia coli has been widely used as a host to clone and express heterologous genes. However, there are few vectors available for cloning and expressing extremely toxic genes, which limits further basic and applied research on extremely toxic proteins. Results In this study, a novel vector pAU10 was constructed in E. coli. pAU10 utilizes the combination of the efficient but highly repressible T7-lacO promoter/operator and the strong rrnBT2 transcriptional terminator upstream of the T7 promoter to strictly control unwanted transcription of the extremely toxic gene, and the trp promoter/operator is oriented opposite to the T7 promoter to control production of the antisense RNA that may block translation of leaky mRNA. Without the supplementation of IPTG and L-tryptophan in the culture medium, transcription of the extremely toxic gene by the T7 promoter is highly repressed, and the trp promoter produces the antisense RNA, which strictly prevents unwanted expression of the extremely toxic protein in E. coli. With the supplementation of IPTG and L-tryptophan, the T7 promoter efficiently transcribes the extremely toxic gene, and the trp promoter does not produce the antisense RNA, ensuring efficient expression of the extremely toxic protein in E. coli. Tight regulation and efficiency of expression of an extremely toxic gene cloned in the vector pAU10 was confirmed by the cloning and expression of the restriction endonuclease-encoding gene bamHI without its corresponding methylase gene in E. coli JM109(DE3). Conclusion pAU10 is a good vector used for cloning and expressing extremely toxic genes in E. coli.

      PubDate: 2017-10-15T16:59:10Z
      DOI: 10.1016/j.ejbt.2017.10.004
  • Simplified methodology for large scale isolation of homozygous transgenic
           lines of lettuce

    • Authors: Flavia S. Darqui; Laura M. Radonic; Nilda López; H. Esteban Hopp; Marisa López Bilbao
      Abstract: Publication date: Available online 9 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Flavia S. Darqui, Laura M. Radonic, Nilda López, H. Esteban Hopp, Marisa López Bilbao
      Background Lettuce is a worldwide cultivated and consumed leafy vegetable and a model plant for biotechnology, due to its adaptability to tissue culture and to stable genetic transformation. Lettuce is also crucial for functional genomics research in Asteraceae, the largest plant family that includes species of great agronomical importance. Kanamycin is the most popular selective agent for in vitro selection of transgenic shoots expressing nptII genetic marker. Results In this work, we adjusted the selection conditions of transgenic seedlings to avoid any escapes, finding that threshold concentration of kanamycin was 75mg/L. To monitor the selection system, we studied the morphological response of transgenic and non-transgenic seedlings in the presence of kanamycin to look for a visual morphological marker. Several traits such as shoot length, primary root length, number of leaves, fresh weight, appearance of the aerial part and development of lateral roots, were affected in non-transgenic seedlings after 30d of culture in selective media. However, only the lateral root development showed an early, qualitative and reliable association with nptII presence as corroborated by PCR detection. Applied in successive transgenic progenies, this method of selection combined with morphological follow up allowed selecting the homozygous presence of nptII gene in 100% of the plants analyzed from T2 to T5. Conclusions This protocol allows a simplified scaling up of the production of multiple homozygous transgenic progeny lines in the early generations avoiding expensive and time-consuming molecular assays.

      PubDate: 2017-10-15T16:59:10Z
      DOI: 10.1016/j.ejbt.2017.10.002
  • Effect of synthetic and natural media on lipid production from Fusarium

    • Authors: Leonidas Matsakas; Maria Giannakou; Dimitrij Vörös
      Abstract: Publication date: Available online 9 October 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Leonidas Matsakas, Maria Giannakou, Dimitrij Vörös
      Background Dependence on fossil resources, for the production of fuels and energy, has resulted in environmental and financial problems, which require our immediate action in order to reverse the situation. Use of renewable sources for the production of fuels and energy is an important alternative with biodiesel remains as one of the promising options. Aim of this work is to evaluate the fungus Fusarium oxysporum for its potentials to accumulate microbial lipids when grown on synthetic media and saccharified sweet sorghum stalks. Results The effect of different carbon sources, nitrogen sources and C/N ratio on the lipid production was initially examined, which resulted in a lipid concentration of 4.4g/L, with lipid content of 42.6% w/w. Sweet sorghum stalks were able to support growth and lipid production of the fungus, both as carbon source and as nitrogen source. It was also shown that saccharification of the dried stalks is an important step to increase lipid production. Removal of the remaining stalk solids enabled the lipid production during cultivation in increased initial solids of up to 16 w/w. This resulted in a lipid production of 3.81g/L. Conclusions It was demonstrated that F. oxysporum can be used as an efficient oleaginous microorganism, with sweet sorghum serving as an excellent raw material for the cultivation of the fungus. The lipids obtained during this work were also found to have a fatty acid profile with good potentials to be used for biodiesel production.

      PubDate: 2017-10-15T16:59:10Z
      DOI: 10.1016/j.ejbt.2017.10.003
  • In vivo assay to identify bacteria with β-glucosidase activity

    • Authors: Erwin Strahsburger; Ana Maria Lopez de Lacey; Ilaria Marotti; Diana DiGioia; Bruno Biavati; Giovanni Dinelli
      Abstract: Publication date: Available online 25 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Erwin Strahsburger, Ana Maria Lopez de Lacey, Ilaria Marotti, Diana DiGioia, Bruno Biavati, Giovanni Dinelli
      Background β-glucosidase assay is performed with purified or semipurified enzymes extracted from cell lysis. However, in screening studies to find bacteria with β-glucosidase activity among many tested bacteria, a fast method without cell lysis is desirable. In that sense, we report an in vivo β-glucosidase assay as fast method to find β-glucosidase producer strain. Results The method consists in growth the tested strains in a medium supplemented with the artificial substrate p-nitrophenyl-β-glucopyranoside (pNPG). The presence of β-glucosidase enzymes converts the substrate in p-Nitrophenol (pNP), a molecule easily measured in the supernatant at 405nm by a spectrophotometer. The assay was evaluated using two Bifidobacterium strains; Bifidobacterium longum B7254 strain that lack of β-glucosidase activity and Bifidobacterium pseudocatenulatum B7003 strain that shows β-glucosidase activity. The addition of sodium carbonate during pNP measurement increases the sensitivity of pNP detection and avoid masking absorbance by culture medium. Furthermore, we shown that pNP is a stable enzymatic product, not metabolized by bacteria, but with an inhibitory effect on cell growth. The β-glucosidase activity was declared as unit of enzyme per gram per minute per dry cell weight. This method also allowed to identify Lactobacillus strains with higher β-glucosidase activity among several lactobacillus species. Conclusion This in vivo β-glucosidase assay can be used as an enzymatic test on living cells without cell disruption. The method is simple, quantitatively and recommended, especially in screening studies driven not only to find bacteria with β-glucosidase activity, but rather the higher β-glucosidase activity among them.

      PubDate: 2017-09-30T11:16:05Z
      DOI: 10.1016/j.ejbt.2017.08.010
  • Effects of fermentation conditions on valuable products of ethanolic
           fungus Mucor indicus

    • Authors: Shabnam Sharifyazd; Keikhosro Karimi
      Abstract: Publication date: Available online 22 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Shabnam Sharifyazd, Keikhosro Karimi
      Background Mucor indicus is a dimorphic fungus for the production of ethanol, oil, protein, and glucosamine. It can ferment different pentoses as well as hexoses; however, the yields of products highly depend on the nutrients and cultivation conditions. In this study, effects of different morphologic forms, cultivation time and temperature, presence or absence of oxygen, carbon sources, and concentration of nitrogen source on the products of M. indicus were investigated. Results The fungus with all morphologies produced high yields of ethanol, in the range of 0.32–0.43g/g, on glucose. However, the fungus with filamentous morphology produced higher amounts of oil, protein, phosphate, and glucosamine together with ethanol, compared with other morphologies. A higher amount of oil (0.145g/g biomass) was produced at 28°C, while the best temperature for protein and glucosamine production was 32 and 37°C, respectively. Although ethanol was produced at higher yield (0.44g/g) under anaerobic conditions compared with aerobic conditions (yield of 0.41g/g), aerobic cultivation resulted in higher yields of protein (0.51g/g biomass), glucosamine (0.16g/g AIM), and phosphate (0.11g/g AIM). Conclusions It is not possible to have the maximum amounts of the products simultaneously. The fermentation conditions and composition of culture media determine the products yields. Carbon source type and the addition of nitrogen source are among the most influencing factors on the product yields. Moreover, all measured products were made with higher yields in cultivation on glucose, except glucosamine, which was produced with higher yields on xylose.

      PubDate: 2017-09-24T07:55:17Z
      DOI: 10.1016/j.ejbt.2017.09.003
  • Poly(DL-Lactide)-degrading enzyme production by immobilized Actinomadura
           keratinilytica strain T16-1 in a 5 L fermenter under various fermentation

    • Authors: Titiporn Panyachanakul; Vichien Kitpreechavanich; Shinji Tokuyama; Sukhumaporn Krajangsang
      Abstract: Publication date: Available online 21 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Titiporn Panyachanakul, Vichien Kitpreechavanich, Shinji Tokuyama, Sukhumaporn Krajangsang
      Background Poly (DL-lactic acid) or PDLLA, a biodegradable polymer, can be hydrolyzed by various types of enzymes. The protease produced by Actinomadura keratinilytica strain T16–1 was previously reported as having PDLLA depolymerase potential. However, the study of PDLLA-degrading enzyme production by bacterial strain is limited. Therefore, the aims of this study are to determine a suitable immobilization material for PDLLA-degrading enzyme production and to optimize PDLLA-degrading enzyme production by using immobilized A. keratinilytica strain T16–1 under various fermentation process conditions in a stirrer fermenter. Results Among tested immobilization materials, a scrub pad was the best immobilizer, giving enzyme activity of 30.03U/ml in a shake flask scale. The maximum enzyme activity was obtained at aeration 0.25 vvm, agitation 170rpm, 45°C and 48h of cultivation time. Under these conditions, PDLLA -degrading enzyme production of 766.33U/ml with 15.97U/ml.h productivity was observed using batch fermentation in a 5L stirrer fermenter. Increased enzyme activity and productivity were observed in repeated-batch (942.67U/ml and 19.64U/ml.h) and continuous fermentation (796.43U/ml and 16.58U/ml.h) at the dilution rate of 0.013 1/h. Scaled-up production of the enzyme in a 10L stirrer bioreactor using the optimized conditions showed a maximum enzyme activity of 578.67U/ml and a productivity of 12.06U/ml.h. Conclusions This work is successfully scaled up the enzyme production to 5 and 10L in a stirrer fermenter and help for many applications of PLA.

      PubDate: 2017-09-24T07:55:17Z
      DOI: 10.1016/j.ejbt.2017.09.001
  • Co-production of hydrogen and ethanol by Escherichia coli SS1 and its

    • Authors: Chiu-Shyan Soo; Wai-Sum Yap; Wei-Min Hon; Norhayati Ramli; Umi Kalsom Md Shah; Lai-Yee Phang
      Abstract: Publication date: Available online 20 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Chiu-Shyan Soo, Wai-Sum Yap, Wei-Min Hon, Norhayati Ramli, Umi Kalsom Md Shah, Lai-Yee Phang
      Background The development of a potential single culture that can co-produce hydrogen and ethanol is beneficial for industrial application. Strain improvement via molecular approach was proposed on hydrogen and ethanol co-producing bacterium, Escherichia coli SS1. Thus, the effect of additional copy of native hydrogenase gene hybC on hydrogen and ethanol co-production by E. coli SS1 was investigated. Results Both E. coli SS1 and the recombinant hybC were subjected to fermentation using 10g/L of glycerol at initial pH7.5. Recombinant hybC had about 2-fold higher cell growth, 5.2-fold higher glycerol consumption rate and 3-fold higher ethanol productivity in comparison to wild-type SS1. Nevertheless, wild-type SS1 reported hydrogen yield of 0.57mol/mol glycerol and ethanol yield of 0.88mol/mol glycerol, which were 4- and 1.4-fold higher in comparison to recombinant hybC. Glucose fermentation was also conducted for comparison study. The performance of wild-type SS1 and recombinant hybC showed relatively similar results during glucose fermentation. Additional copy of hybC gene could manipulate the glycerol metabolic pathway of E. coli SS1 under slightly alkaline condition. Conclusions HybC could improve glycerol consumption rate and ethanol productivity of E. coli despite lower hydrogen and ethanol yields. Higher glycerol consumption rate of recombinant hybC could be an advantage for bioconversion of glycerol into biofuels. This study could serve as a useful guidance for dissecting the role of hydrogenase in glycerol metabolism and future development of effective strain for biofuels production.

      PubDate: 2017-09-24T07:55:17Z
      DOI: 10.1016/j.ejbt.2017.09.002
  • Genetic analysis of Penthorum chinense Pursh. By improved-RAPD and ISSR in

    • Authors: Zhiqiang Mei; Xianqin Zhang; Asaduzzaman Khan; Saber Imani; Xiaoyan Liu; Hui Zou; Chunli Wei; Junjiang Fu
      Abstract: Publication date: Available online 7 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Zhiqiang Mei, Xianqin Zhang, Asaduzzaman Khan, Saber Imani, Xiaoyan Liu, Hui Zou, Chunli Wei, Junjiang Fu
      Background Penthorum chinense Pursh. (P. chinense) is a well-known traditional Chinese medicine (TCM), which has long been used for prevention and treatment of liver and hepatic diseases. This study aimed to genetically characterize the varieties of P. chinense from different geographic localities of China, by randomly amplified polymorphic DNA (RAPD)-PCR technique, and verified with inter-simple sequence repeats (ISSRs) markers. Results Twenty P. chinense samples were collected from 9 different geographic localities. Previously improved-RAPD and ISSR markers were utilized for genetic analysis on the basis of DNA amplification. The genetic relationship dendrogram was obtained by conducting cluster analysis to the similarity coefficient of improved-RAPD and ISSR markers. Improved-RAPD yielded 185 scorable amplified products, of which 68.6% of the bands were found polymorphic with an average amplification of 9.25 bands per primer. The ISSR markers revealed 156 alleles with 7.8 bands per primers, where 59.7% bands were found polymorphic. Furthermore, the similarity coefficient ranged of RAPD and ISSR markers were 0.71–0.91 and 0.66–0.89 respectively. Conclusions This study indicated that improved-RAPD and ISSR methods are useful tools for genetic diversity and characterization of P. chinense. Our findings could provide theoretical basis for cultivar identification, standardization, and molecular-assisted breeding of P. chinense in medicinal use.

      PubDate: 2017-09-12T03:45:47Z
      DOI: 10.1016/j.ejbt.2017.08.008
  • Selection of Schizochytrium limacinum mutants based on butanol tolerance

    • Authors: Demao Li; Ke Zhang; Limei Chen; Mengxun Ding; Minli Zhao; Shulin Chen
      Abstract: Publication date: Available online 6 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Demao Li, Ke Zhang, Limei Chen, Mengxun Ding, Minli Zhao, Shulin Chen
      Background Mutation breeding is one of the most important routes to achieving high docosahexaenoic acid (DHA) productivity using Schizochytrium. However, few selection strategies have been reported that aim to generate a high DHA content in Schizochytrium lipids. Results First, culture temperature altered the butanol tolerance of Schizochytrium limacinum B4D1. Second, S. limacinum E6 was obtained by selecting mutants with high butanol tolerance. This mutant exhibited a 17.97% lower proportion of DHA than the parent strain S. limacinum B4D1. Third, a negative selection strategy was designed in which S. limacinum F6, a mutant with poor butanol tolerance, was obtained. The proportion of DHA in S. limacinum F6 was 11.22% higher than that of parent strain S. limacinum B4D1. Finally, the performances of S. limacinum B4D1, E8 and F6 were compared. These three strains had different fatty acid profiles, but there was no statistical difference in their biomasses and lipid yields. Conclusion It was feasible to identified the relative DHA content of S. limacinum mutants based on their butanol tolerance.

      PubDate: 2017-09-12T03:45:47Z
      DOI: 10.1016/j.ejbt.2017.08.009
  • Evaluation of alkaline, thermotolerant lipase from an indigenous isolated
           Bacillus strain for detergent formulation

    • Authors: Rashmi Saraswat; Vijeshwar Verma; Srinivas Sistla; Indu Bhushan
      Abstract: Publication date: Available online 5 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Rashmi Saraswat, Vijeshwar Verma, Srinivas Sistla, Indu Bhushan
      Background Lipases are utilised in detergent industries to minimise usage of phosphate-based chemicals in detergent formulations. The use of lipase in household laundry reduce environment pollution and enhances the ability of detergent to remove tough oil or grease stains. Results A lipase producing indigenous Bacillus subtilis strain [accession no. KT985358] was isolated from the foothills of Trikuta mountain in Jammu and Kashmir, India. The lipase (BSK-L) produced from this strain expressed alkaline and thermotolerant characters. Lipase has a optimal activity at pH8.0 and at temperature 37°C, whereas it was found to be stable at pH range 6.0 to 9.0 and showed active lipolytic activity at temperature range 30°C to 60°C. Furthermore, lipase activity was found to be stimulated in the presence of metal ions, Mn2+, K+, Zn2+, Fe2+ and Ca2+. This lipase was observed to be resistant to surfactants, oxidising agents and commercial detergents, suggesting it as a potential candidate for detergent formulation. BSK-L displayed noticeable capability to remove oil stains when used in different washing solutions containing buffer, lipase and commercial detergent. The maximum olive oil removal percentage obtained was 68% when the optimum detergent concentration (Fena) was 0.3%. The oil removal percentage from olive oil soiled cotton fabric was found to be increased with 40U/ml of lipase. Conclusions This BSK-L enzyme has the potential for removing oil stains by developing a pre-soaked solution for detergent formulation and was found compatible with surfactants, oxidising agents, and commercial detergents.

      PubDate: 2017-09-06T01:10:18Z
      DOI: 10.1016/j.ejbt.2017.08.007
  • 1-deoxynojirimycin from Bacillus subtilis improves antioxidant and
           antibacterial activities of juvenile Yoshitomi tilapia

    • Authors: Lining Tang; Kai Huang; Jun Xie; Dan Yu; Lei Sun; Qing Huang; Yanjun Bi
      Abstract: Publication date: Available online 4 September 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Lining Tang, Kai Huang, Jun Xie, Dan Yu, Lei Sun, Qing Huang, Yanjun Bi
      Background Juvenile Yoshitomi tilapia is often infected by pathogens and results in low-level survival rate. Bacillus subtilis, as a probiotic, may have beneficial effects on Y. tilapia with compound 1-deoxynojirimycin (DNJ), which has antibacterial activities. The effects of dietary probiotic supplementation on Y. tilapias were evaluated. Results Juvenile Y. tilapia was fed with B. subtilis for 56 d. Y. tilapia was infected by Aeromonas hydrophila and survival rate was compared. Dietary B. subtilis increased weight gain rate, specific growth, food conversion ratios and food intake rate of Y. tilapia. The diet improved the cumulative survival rate (CSR) of juvenile Y. tilapia when the concentration of B. subtilis was more than 2.05×1010 cfu/kg and CSR reached a maximum rate when the concentration of bacillus was 4.23×1010 (P <0.05). Meanwhile, B. subtilis improved total antioxidant capacity (TAC), spleen index, the activities of serum lysozyme, alkaline phosphatase (ALP), superoxide dismutase (SOD) and catalase (CAT) (P <0.05). In contrast, B. subtilis reduced serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), and C3 complement (P <0.05). DNJ was isolated from secondary metabolisms and proved to increase the levels of SOD, CAT and reduce the levels of AST, ALT and MDA at cell levels. After A. hydrophila infection, DNJ prevented the reduction in survival rate of Y. tilapia (P <0.05). Conclusions 1-deoxynojirimycin from Bacillus subtilis can be used to improve the growth performance of juvenile Y. tilapia by affecting its antioxidant and antibacterial activities.

      PubDate: 2017-09-06T01:10:18Z
      DOI: 10.1016/j.ejbt.2017.08.006
  • Isolation and identification of allergens and biogenic amines of Prosopis
           juliflora genotypes

    • Authors: Abdulrahman A. Al-Soqeer; Qasi D. Alsubaie; Mohamed I. Motawei; Hassan M. Mousa; Ahmed M. Abdel-Salam
      Abstract: Publication date: Available online 24 August 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Abdulrahman A. Al-Soqeer, Qasi D. Alsubaie, Mohamed I. Motawei, Hassan M. Mousa, Ahmed M. Abdel-Salam
      Background Prosopis, or mesquite (Prosopis juliflora (Sw.) DC.) was introduced in Saudi Arabia for several decades, and heavily used in streets, roadsides and parks plantation. It shows a great adaptation to the prevailing climatic conditions such as high temperature, severe drought and salinity, and spread naturally in many parts of the Kingdom. This research was carried out to isolate allergic proteins and biogenic amines from pollen gains of P. juliflora genotypes that exist in Saudi Arabia from two regions (Al-Qassim and Eastern regions). Results The results showed that eighteen different allergic proteins have been detected in Prosopis juliflora genotypes with molecular weight ranging from 14 to 97 KDa. Moreover, Prosopis juliflora genotypes from the two studied regions contained eight biogenic amines, Histamine, Tyramine, Tryptamine, B-Phenylthylamine, Butricine, Codapherine, Spermidine, and Speramine. All genotypes from Al-Qassim region were found to contain all eight amines. While in Eastern region, histamine did not exist in three genotypes, spermine was not found in six genotypes, and spermidine was not recorded in three genotypes. Genotypes B23, E20 and E21 had the lowest biogenic amine. Conclusions All identified proteins from mesquite trees from both Regions (Eastern and Al-Qassim) are allergic for patients sensitive to pollen grains. Bioamines, other than histamine and tyramine, were recorded in varied concentrations from genotype to another.

      PubDate: 2017-08-28T20:54:59Z
      DOI: 10.1016/j.ejbt.2017.08.005
  • Yield and rheological properties of exopolysaccharide from a local
           isolate: Xanthomonas axonopodis pv. vesicatoria

    • Authors: Ahmet Sukru Demirci; Ibrahim Palabıyık; Deniz Damla Altan; Demet Apaydın; Tuncay Gümüs
      Abstract: Publication date: Available online 17 August 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Ahmet Sukru Demirci, Ibrahim Palabıyık, Deniz Damla Altan, Demet Apaydın, Tuncay Gümüs
      Background The aim of the present study was to evaluate gum productivity of a local strain, Xanthomonas axonopodis pv. vesicatoria isolated from pepper plant and its rheological behavior for the first time compared to the standard strain, Xanthomonas campestris DSM 19000 (NRRL B-1459). The influence of operational conditions (agitation rate and inoculum volume) on gum production, and rheological properties of gums from the Xanthomonas strains were investigated. Results The isolated strain of Xanthomonas showed similar xanthan yield compared to the standard strain. Furthermore, this study clearly confirmed that gum yield depended on bacterial strain, agitation rate and inoculum size. The most suitable conditions for the gum production in an orbital shaker in terms of agitation rate and inoculum size were 180rpm and 5%, respectively, resulting in an average production of 10.96 and 11.19g/L for X. axonopodis pv. Vesicatoria and X. campestris DSM 19000, respectively. Regarding the rheological properties, Ostwald de Waeleand power law models were used to describe flow and oscillatory behavior of the gum solutions, respectively. Consistency of the novel gum solution remarkably was much higher than the commercial xanthan gum solution. Flow and oscillatory behavior and their temperature ramps showed that weak gel like structure could be obtained with less gum concentrations when the novel gum was used. Conclusion Therefore, yield and technological properties of the aqueous solutions of the exopolysaccharide synthesized by X. axonopodis pv. Vesicatoria were observed to be more suitable for industrial production.

      PubDate: 2017-08-17T15:59:22Z
      DOI: 10.1016/j.ejbt.2017.08.004
  • Molecular characterization and genetic diversity of different genotypes of
           Oryza sativa and Oryza glaberrima

    • Authors: Caijin Chen; Wenchuang He; Tondi Yacouba Nassirou; Athanase Nsabiyumva; Xilong Dong; Yawo Mawunyo Nevame Adedze; Deming Jin
      Abstract: Publication date: Available online 16 August 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Caijin Chen, Wenchuang He, Tondi Yacouba Nassirou, Athanase Nsabiyumva, Xilong Dong, Yawo Mawunyo Nevame Adedze, Deming Jin
      Background Availability of related rice species is critical for rice breeding and improvement. Two distinct species of domesticated rice exist in the genus Oryza: Oryza sativa (Asian rice) and Oryza glaberrima (African rice). New rice for Africa (NERICA) is derived from interspecific crosses between these two species. Molecular profiling of these germplasms is important for both genetics and breeding studies. We used 30 polymorphic SSR markers to assess the genetic diversity and molecular fingerprints of 53 rice genotypes of O. sativa, O. glaberrima, and NERICA. Results In total, 180 alleles were detected. Average polymorphism information content and Shannon's information index were 0.638 and 1.390, respectively. Population structure and neighbor-joining phylogenetic tree revealed that 53 genotypes grouped into three distinct subpopulations conforming to the original three groups, except three varieties (IR66417, WAB450-4, MZCD74), and that NERICA showed a smaller genetic distance from O. sativa genotypes (0.774) than from O. glaberrima genotypes (0.889). A molecular fingerprint map of the 53 accessions was constructed with a novel encoding method based on the SSR polymorphic alleles. Ten specific SSR markers displayed different allelic profiles between the O. glaberrima and O. sativa genotypes. Conclusions Genetic diversity studies revealed that 50 rice types were clustered into different subpopulations whereas three genotypes were admixtures. Molecular fingerprinting and 10 specific markers were obtained to identify the 53 rice genotypes. These results can facilitate the potential utilization of sibling species in rice breeding and molecular classification of O. sativa and O. glaberrima germplasms.

      PubDate: 2017-08-17T15:59:22Z
      DOI: 10.1016/j.ejbt.2017.08.001
  • Introduction of a synthetic Thermococcus-derived α-amlyase gene into
           barley genome for increased enzyme thermostability in grains

    • Authors: Daniel Mihálik; Marcela Gubišová; Ján Kraic; Martina Hudcovicová; Michaela Havrlentová; Jana Moravčíková; Miroslav Glasa; Ildikó Matušíková
      Abstract: Publication date: Available online 15 August 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Daniel Mihálik, Marcela Gubišová, Ján Kraic, Martina Hudcovicová, Michaela Havrlentová, Jana Moravčíková, Miroslav Glasa, Ildikó Matušíková
      Background The enzymes utilized in the process of beer production are generally sensitive to higher temperatures. About 60% of them are deactivated in drying the malt that limits the utilization of starting material in the fermentation process. Gene transfer from thermophilic bacteria is a promising tool for producing barley grains harboring thermotolerant enzymes. Results Gene for α-amylase from hydrothermal Thermococcus, optimally active at 75–85°C and pH between 5.0 and 5.5, was adapted in silico to barley codon usage. The corresponding sequence was put under control of the endosperm-specific promoter 1Dx5 and after synthesis and cloning transferred into barley by biolistics. In addition to model cultivar Golden Promise we transformed three Slovak barley cultivars Pribina, Levan and Nitran, and transgenic plants were obtained. Expression of the ~50kDa active recombinant enzyme in grains of cvs. Pribina and Nitran resulted in retaining up to 9.39% of enzyme activity upon heating to 75°C, which is more than 4 times higher compared to non-transgenic controls. In the model cv. Golden Promise the grain α-amylase activity upon heating was above 9% either, however, the effects of the introduced enzyme were less pronounced (only 1.22 fold difference compared with non-transgenic barley). Conclusions Expression of the synthetic gene in barley enhanced the residual α-amylase activity in grains at high temperatures.

      PubDate: 2017-08-17T15:59:22Z
      DOI: 10.1016/j.ejbt.2017.08.002
  • Molecular cloning and characterisation of scavenger receptor class B in
           pearl oyster Pinctada fuctada martensii

    • Authors: Lei Chao; Hao Ruijuan; Zheng Zhe; Deng Yuewen; Wang Qingheng; Li Junhui
      Abstract: Publication date: Available online 15 August 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Lei Chao, Hao Ruijuan, Zheng Zhe, Deng Yuewen, Wang Qingheng, Li Junhui
      Background Molluscs can accumulate carotenoids in their body tissues by predominantly feeding on aquatic plant sources. Carotenoid transport and absorption are determined by the regulation of various proteins such as Scavenger receptor class B(SR-BI). We report the identification and characterisation of pearl oyster Pinctada fuctada martensii SR-BI (PmSR-BI). The correlation between total carotenoid content (TCC) and gene expression was also estimated. Results The full-length cDNA of PmSR-BI was 1828bp, including an open-reading frame encoding of 1518bp with a pI value of 5.83. PmSR-BI protein contains a hydrophobic CD36 domain and four centrally clustered cysteine residues for the arrangement of disulphide bridges. The deduced amino acid sequence had an identity of 30% to 60% with the SR-B of other organisms. Reverse transcription polymerase chain reaction analysis showed that mRNA transcripts were expressed in multiple tissues of adult pearl oyster. A higher expression of PmSR-BI gene was observed in the hepatopancreas than in the adductor muscle, gill and mantle. The TCC and gene expression of PmSR-BI were significantly correlated (P <0.05), with a correlation coefficient of 0.978. Conclusions The results suggested that PmSR-BI is involved in the absorption of carotenoids in the pearl oyster P. fuctada martensii.

      PubDate: 2017-08-17T15:59:22Z
      DOI: 10.1016/j.ejbt.2017.08.003
  • The construction and application of novel genetically-engineered
           Aspergillus oryzae for expressing proteases

    • Authors: Xiao-Chun Yu; Shi-Liang Ma; Yan Xu; Cheng-Hao Fu; Chun-Ying Jiang; Chen-Yu Zhou
      Abstract: Publication date: Available online 20 July 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Xiao-Chun Yu, Shi-Liang Ma, Yan Xu, Cheng-Hao Fu, Chun-Ying Jiang, Chen-Yu Zhou
      Background To test the possibilities of improving the polypeptide production from soybean meal fermentation by engineered Aspergillus oryzae strains. Four different protease genes were cloned and transformed into the wild-type A. oryzae, and the engineered A. oryzae strains were then used for soybean meal fermentation. Results The results showed different degrees of improvement in the protease activity of the four transformants, when compared with wild-type A. oryzae. A major improvement in the polypeptide yield was achieved when these strains were used in soybean meal fermentation. The polypeptide conversion rate of one of the four transformants, A. oryzae pep, reached 35.9%, which was about twofold higher than that exhibited by wild-type A. oryzae. Amino acids content analysis showed that the essential amino acids content and amino acids composition of the fermentation product were significantly improved when engineered A. oryzae strains were used for soybean meal fermentation. Conclusions These findings suggest that cloning of microbial protease genes with good physicochemical properties and expressing them in an ideal host such as A. oryzae is a novel strategy to enhance the value of soybean meal.

      PubDate: 2017-07-23T08:22:05Z
      DOI: 10.1016/j.ejbt.2017.07.004
  • Transcriptome analysis of female and male flower buds of Idesia polycarpa
           Maxim. var. vestita Diels

    • Authors: Lanju Mei; Na Dong; Fosheng Li; Na Li; Min Yao; Fang Chen; Lin Tang
      Abstract: Publication date: Available online 13 July 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Lanju Mei, Na Dong, Fosheng Li, Na Li, Min Yao, Fang Chen, Lin Tang
      Background Idesia polycarpa Maxim. var. vestita Diels, a dioecious plant, is widely used for biodiesel due to the high oil content of its fruits. However, it is hard to distinguish its sex in the seedling stage, which makes breeding and production problematic as only the female tree can produce fruits, and the mechanisms underlying sex determination and differentiation remain unknown due to the lack of available genomic and transcriptomic information. To begin addressing this issue, we performed the transcriptome analysis of its female and male flower. Results 28,668,977 and 22,227,992 clean reads were obtained from the female and male cDNA libraries, respectively. After quality checks and de novo assembly, a total of 84,213 unigenes with an average length of 1179bp were generated and 65,972 unigenes (78.34%) could be matched in at least one of the NR, NT, Swiss-Prot, COG, KEGG and GO databases. Functional annotation of the unigenes uncovered diverse biological functions and processes, including reproduction and developmental process, which may play roles in sex determination and differentiation. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed many unigenes annotated as metabolic pathways, biosynthesis of secondary metabolites pathways, plant–pathogen interaction, and plant hormone signal transduction. Moreover, 29,953 simple sequence repeats were identified using the microsatellite software. Conclusion This work provides the first detailed transcriptome analysis of female and male flower of I. polycarpa and lays foundations for future studies on the molecular mechanisms underlying flower bud development of I. polycarpa.

      PubDate: 2017-07-23T08:22:05Z
      DOI: 10.1016/j.ejbt.2017.07.002
  • Early bacterial biofilm colonizers in the coastal waters of Mauritius

    • Authors: Sillma Rampadarath; Kushlata Bandhoa; Daneshwar Puchooa; Rajesh Jeewon; Subhasisa Bal
      Abstract: Publication date: Available online 4 July 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Sillma Rampadarath, Kushlata Bandhoa, Daneshwar Puchooa, Rajesh Jeewon, Subhasisa Bal
      Background The past years have witnessed a growing number of researches in biofilm forming communities due to their environmental and maritime industrial implications. To gain a better understanding of the early bacterial biofilm community, microfiber nets were used as artificial substrates and incubated for a period of 24h in Mauritian coastal waters. Next-generation sequencing technologies were employed as a tool for identification of early bacterial communities. Different genes associated with quorum sensing and cell motility were further investigated. Results Proteobacteria were identified as the predominant bacterial microorganisms in the biofilm within the 24h incubation, of which members affiliated to Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria were among the most abundant classes. The biofilm community patterns were also driven by phyla such as Firmicutes, Bacteroidetes, Chloroflexi, Actinobacteria and Verrucomicrobia. The functional analysis based on KEGG classification indicated high activities in carbohydrate, lipid and amino acids metabolism. Different genes encoding for luxI, lasI, agrC, flhA, cheA and cheB showed the involvement of microbial members in quorum sensing and cell motility. Conclusion This study provides both an insight on the early bacterial biofilm forming community and the genes involved in quorum sensing and bacterial cell motility.

      PubDate: 2017-07-12T02:39:04Z
      DOI: 10.1016/j.ejbt.2017.06.006
  • Proteolytic activity of recombinant DegP from Chromohalobacter salexigens

    • Authors: Dewi Fitriani; M. Saifur Rohman; Irfan D. Prijambada
      Abstract: Publication date: Available online 28 June 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Dewi Fitriani, M. Saifur Rohman, Irfan D. Prijambada
      Background DegP is serine protease that specifically cleaves and refolds unfolding proteins in peripalsmic space of the cells. So far, there is no information regarding the DegP from halophilic bacterium. Chromohalobacter salexigens BKL5 is a moderately halophilic bacterium that has an ability to grow in a media containing more than 15% salt. Therefore, the objectives of this work were to clone and overexpress DegP encoding gene from Chromohalobacter salexigens BKL5 and characterize its biochemical properties. Results DegP-encoding gene could be overexpressed in Escherichia coli BL21(DE3) CodonPlus in an active form. SDS-PAGE analysis showed that the molecular weight of the recombinant DegP was 45kDa. Size exclusion chromatography analysis suggested that recombinant DegP was present in two multimeric states, hexameric and dodecameric, with molecular weights of 297.9kDa and 579.12kDa, respectively. Both conformations were enzymatically active when casein was used as substrate for enzymatic assay. Circular dichroism analysis showed that recombinant DegP was composed of 0.21–0.29 helical content, which was comparable to the helical content in the crystal structure of E. coli DegP. The basic/acidic ratio of recombinant DegP was 0.56, which was slightly higher than that of the average basic/acidic ratio of extreme halophilic (0.45) but significantly lower than that of non halophilic (0.94). Conclusions Recombinant DegP from Chromohalobacter salexigens BKL5 showed proteolytic activity when β-casein was used as a substrate. In silico analysis indicated that recombinant DegP had similar characteristics to halophilic proteins based on its amino acid composition.

      PubDate: 2017-07-03T14:06:50Z
      DOI: 10.1016/j.ejbt.2017.06.004
  • Structural and mechanical characterization of custom design cranial
           implant created using additive manufacturing

    • Authors: Khaja Moiduddin; Saied Darwish; Abdulrahman Al-Ahmari; Sherif ElWatidy; Ashfaq Mohammad; Wadea Ameen
      Abstract: Publication date: Available online 28 June 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Khaja Moiduddin, Saied Darwish, Abdulrahman Al-Ahmari, Sherif ElWatidy, Ashfaq Mohammad, Wadea Ameen
      Background Reconstruction of customized cranial implants with a mesh structure using computer-assisted design and additive manufacturing improves the implant design, surgical planning, defect evaluation, implant-tissue interaction and surgeon's accuracy. The objective of this study is to design, develop and fabricate cranial implant with mechanical properties closer to that of bone and drastically decreases the implant failure and to improve the esthetic outcome in cranial surgery with precision fitting for a better quality of life. A customized cranial mesh implant is designed digitally, based on the Digital Imaging and Communication in Medicine files and fabricated using state of the Art-Electron Beam Melting an Additive Manufacturing technology. The EBM produced titanium implant was evaluated based on their mechanical strength and structural characterization. Results The result shows, the produced mesh implants have a high permeability of bone ingrowth with its reduced weight and modulus of elasticity closer to that the natural bone thus reducing the stress shielding effect. Scanning electron microscope and micro-computed tomography (CT) scanning confirms, that the produced cranial implant has a highly regular pattern of the porous structure with interconnected channels without any internal defect and voids. Conclusions The study reveals that the use of mesh implants in cranial reconstruction satisfies the need of lighter implants with an adequate mechanical strength, thus restoring better functionality and esthetic outcomes for the patients.

      PubDate: 2017-07-03T14:06:50Z
      DOI: 10.1016/j.ejbt.2017.06.005
  • Putative 3-nitrotyrosine detoxifying genes identified in the yeast
           Debaryomyces hansenii: In silico search of regulatory sequences responsive
           to salt and nitrogen stress

    • Authors: Daniela E. Castro; Miguel Murguía-Romero; Patricia E. Thomé; Antonio Peña; Marissa Calderón-Torres
      Abstract: Publication date: Available online 15 June 2017
      Source:Electronic Journal of Biotechnology
      Author(s): Daniela E. Castro, Miguel Murguía-Romero, Patricia E. Thomé, Antonio Peña, Marissa Calderón-Torres
      Background During saline stress, the yeast Debaryomyces hansenii has as a strategy to avoid the oxidation of proteins the synthesis of tyrosine, which reacts with nitrogen radicals to form 3-nitrotyrosine, these contributes to the high halotolerace of the yeast, because it prevents the effects of associated oxidative stress. However, it has not been determined how does D. hansenii counteract the presence of this toxic compound. In this work we evaluated the D. hansenii capacity to assimilate 3-nitrotyrosine as a unique nitrogen source, and measured its denitrase activity under NaCl stress. In order to identify putative genes related to the assimilation of 3-nitrotyrosine, we performed an in silico search in the promoter regions of D. hansenii genome. Results We identified 15 genes whose promoter had binding sequences for transcriptional factors of sodium, nitrogen and oxidative stress with oxidoreductase and monooxygenase GO annotations. Two of these genes, DEHA2E24178g and DEHA2C00286g coding for putative denitrases and having GATA sequences, evaluated by RT-PCR, showed a high expression in sodium and nitrogen stress. Conclusions D. hansenii can grow in presence of 3-nitrotyrosine as the only nitrogen source, and have a high especific denitrase activity to degradate 3-nitrotyrosine in 1 and 2M NaCl stress conditions. The results suggest that given the lack of information for transcriptional factors in D. hansenii, genes identified by our in silico analysis may help to explain 3-nitrotyrosine assimilation mechanisms.

      PubDate: 2017-06-17T15:12:54Z
      DOI: 10.1016/j.ejbt.2017.06.003
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