Journal of Microbiology and Biotechnology (J Microbiol Biotechnol )

Publisher: Hanʼguk Sanŏp Misaengmul Hakhoe

Description

Impact factor 1.32

  • Hide impact factor history
     
    Impact factor
  • 5-year impact
    1.47
  • Cited half-life
    4.60
  • Immediacy index
    0.12
  • Eigenfactor
    0.01
  • Article influence
    0.37
  • Website
    Journal of Microbiology and Biotechnology website
  • ISSN
    1017-7825
  • OCLC
    261226927
  • Material type
    Document, Periodical, Internet resource
  • Document type
    Internet Resource, Computer File, Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The entire nucleotide sequence of the TKL1 gene encoding transketolase (TKL) in an erythritolproducing yeast of Candida magnoliae was determined by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed an open reading frame of C. magnoliae TKL1 (CmTKL1) that spans 2,088 bp and encodes 696 amino acids, sharing 61.7% amino acid identity to Kluyveromyces lactis TKL. Functional analysis showed that CmTKL1 complemented a Saccharomyces cerevisiae tkl1 tkl2 double mutant for growth in the absence of aromatic amino acids and restored transketolase activity in this mutant. An enzyme activity assay and RT-PCR revealed that the expression of CmTKL1 is induced by fructose, H2O2, and KCl. The GenBank accession number for C. magnoliae TKL1 is KF751756.
    Journal of Microbiology and Biotechnology 10/2014; 24(10):1389-96.
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    ABSTRACT: Lycopene, which is a well-known red carotenoid pigments, has been drawing scientific interest because of its potential biological functions. The current study reports that lycopene acts as a bactericidal agent by inducing reactive oxygen species (ROS)-mediated DNA damage in Escherichia coli. Lycopene treatment elevated the level ROS-in particular hydroxyl radicals ((•)OH) -which can damage DNA in E. coli. Lycopene-induced DNA damage in bacteria was confirmed and we also observed cell filamentation caused by cell division arrest, an indirect marker of DNA damage repair system, in lycopene-treated E. coli. Increased RecA expression was observed, indicating activation of the DNA repair system (SOS response). To summarize, lycopene exerts its antibacterial effects by inducing (•)OH -mediated DNA damage that cannot be ameliorated by the SOS response. Lycopene may be a clinically useful adjuvant for current antimicrobial therapies.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: A metagenomic fosmid library was constructed using genomic DNA isolated from the gut microflora of Hermetia illucens, a black soldier fly. A cellulase positive clone, CS10 gene was identified by the extensive Congo-red overlay screenings for cellulase activity from the fosmid library of 92,000 clones. The CS10 gene was composed of the 996 bp DNA sequence encoding the mature protein of 331 amino acids. The deduced amino acids of CS10 gene showed 72% sequence identity with glycosyl hydrolase family 5 gene of Dysgonomonas mossii, displaying no significant sequence homology to already known cellulases. The purified CS10 protein presented a single band of cellulase activity with a molecular weight of approximately 40 kDa on SDS-PAGE and zymogram. The purified CS10 protein exhibited the optimal activity at 50°C and pH 7.0, and the thermostability and pH stability of CS10 were preserved at the ranges of 20~50°C and pH 4.0~10.0. CS10 exhibited little loss of cellulase activity against various chemical reagents such as 10% polar organic solvents, 1% non-ionic detergents, and 0.5 M denaturing agents. Also, the substrate specificity and the product patterns by thin-layer chromatography suggested that CS10 is an endo-β-1,4-glucanase. From these biochemical properties of CS10, it is expected that the enzyme have the potential possibility for application in industrial processes.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: This article focuses on the effects of glycine betaine on preventing caramelization, and increasing DCW and L-lysine production. The additional glycine betaine not only decreased the browning intensity (decreased 4 times), the concentration of 5-hydroxymethylfurfural (decreased 7.8 times) and furfural (decreased 12 times), but also increased the availability of glucose (increased 17.5%) for L-lysine production. The DCW and L-lysine production were increased by adding no more than 20 mM glycine betaine, whereas the DCW and L-lysine production were decreased along with the reduction of pH values, although pH had a better response to prevent caramelization than that of glycine betaine. For L-lysine production, the highest increase (40%) was observed on the media with 20 mM glycine betaine. The crucial enzymes in glycolysis and L-lysine biosynthesis pathway were investigated. And the results indicated that additional glycine betaine increases the activity of enzymes in glycolysis, in contrast to the effect of pH. All the results indicated that glycine betaine can be used to prevent caramelization and increase the L-lysine production. By applying this strategy, glucose won't be have to separate from the culture media during autoclaving so that the factories can save production costs and shorten fermentation period.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: Proteus vulgaris K80 lipase was expressed in Escherichia coli BL21 (DE3) cells and immobilized on amine-terminated magnetic microparticles (Mag-MPs). Immobilization yield and activity retention were 84.15% and 7.87%, respectively. A homology model of lipase K80 was constructed using P. mirabilis lipase as the template. Many lysine residues were located on the protein surface remote from active sites. The biochemical characteristics of immobilized lipase K80 were compared with the soluble free form of lipase K80. The optimum temperature of K80-Mag-MPs was 60oC, which was 20oC higher than that of the soluble form. K80-Mag-MPs also tended to be more stable than the soluble form at elevated temperatures and a broad range of pH. K80-Mag-MP maintained its stable form at up to 40oC and in a pH range of 5.0-10.0, whereas soluble K80 maintained its activity up to 35oC and pH 6.0-10.0. K80-Mag-MPs had broader substrate specificity compared to that of soluble K80. K80-Mag-MPs showed about 80% residual relative activity after 5 recovery trials. These results indicate the potential benefit of K80-Mag-MPs as a biocatalyst in various industries.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: Enzymatic hydrolysis of lignocellulosic biomass into fermentable sugars is a key step in conversion of agricultural by-products to biofuels and value-added chemicals. Utilization of a robust microorganism for on-site production of biomass-degrading enzymes has gained increasing interest as an economical approach for supplying enzymes to biorefinery processes. In this study, production of multi-polysaccharide degrading enzymes from Aspergillus aculeatus BCC199 by solid-state fermentation was improved through the statistical design approach. Among the operational parameters, yeast extract and soybean meal as well as a non-ionic surfactant Tween 20 and initial pH were found as key parameters for maximizing production of cellulolytic and hemicellulolytic enzymes. Under optimized condition, the production of FPase, endoglucanase, β-glucosidase, xylanase, and β-xylosidase were achieved at 23, 663, 88, 1,633, and 90 units/g of dry substrate, respectively. The multi-enzyme extract was highly efficient in saccharification of alkaline-pretreated rice straw, corn cob, and corn stover. In comparison to commercial cellulase preparations, the BCC199 enzyme mixture was able to produce remarkable yields of glucose and xylose, as it contains higher relative activities of β-glucosidase and core hemicellulases (xylanase, β-xylosidase). These results suggested that the crude enzyme extract from A. aculeatus BCC199 possess balanced cellulolytic and xylanolytic activities required for efficient saccharification of lignocellulosic biomass feedstocks and supplementation of external β-glucosidase or xylanase was dispensable. The work, thus, demonstrates the high potential of A. aculeatus BCC199 as a promising producer of lignocellulose-degrading enzymes for biomass conversion industry.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: In order to discover and develop novel signaling inhibitors from plants, a screening system was established targeting the two-component system of Cryptococcus neoformans by using the wild type and a calcineurin mutant of C. neoformans, based on the counter-regulatory action of high-osmolarity glycerol (Hog1) mitogen-activated protein kinase (MAPK) and the calcineurin pathways in C. neoformans. Among 10,000 plant extracts, that from Harrisonia abyssinica Oliv. exhibited the most potent inhibitory activity against C. neoformans var. grubii H99 with fludioxonil. Bioassay-guided fractionation was used to isolate two bioactive compounds from H. abyssinica and these compounds were identified as chebulagic acid and chebulanin using spectroscopic methods. These compounds specifically inhibited the calcineurin pathway in C. neoformans. Moreover, they exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentrations (MICs) ranging from 0.25 to over 64 µg/ml.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: Recently, multifunctional nanomaterials have been developed as nanotherapeutic agents for cellular imaging and targeted cancer treatment because of their ease of synthesis and low cytotoxicity. In this study, we developed a multifunctional, two-component nanorod consisting of gold (Au) and nickel (Ni) blocks that enables dual-fluorescence imaging and the targeted delivery of small interfering RNA (siRNA) to improve cancer treatment. Fluorescein isothiocyanate-labeled luteinizing hormone-releasing hormone (LHRH) peptides were attached to the surface of a Ni block via a histidine-tagged LHRH interaction to specifically bind to a breast cancer cell line, MCF-7. The Au block was modified with TAMRA-labeled thiolated siRNA in order to knock down the vascular endothelial growth factor (VEGF) protein to inhibit cancer growth. These two-component nanorods actively target and internalize into MCF-7 cells to induce apoptosis through RNA interference. This study demonstrates the feasibility of using two-component nanorods as a potential theranostic in breast cancer treatment with capabilities in dual imaging and targeted gene delivery.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: Lysozyme is a protein found in egg white, tears, saliva, and other secretions. As a marketable natural alternative to preservative, lysozyme can act as a natural antibiotic. In this study, we have isolated Bacillus lincheniformis TIB320 from soil which contains a lysozyme gene with various features. We have cloned and expressed the lysozyme in E.coli. The antimicrobial activity of lysozyme showed that it had a broad antimicrobial spectrum against several standard strains. The lysozyme can maintain efficient activities in a pH range between 3 and 9 and from 20 oC to 60 oC, respectively. The lysozyme was resistant to the pepsin and trypsin to some extent at 40 oC. Production of the lysozyme was optimized by using various expression strategies in B. subtilis WB800. The lysozyme from Baclicus lincheniformis TIB320 will be a promising choice for food additive and feed additive.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: In the present study, an anthraquinone derivative, questinol was successfully isolated from the broth extract of the marine derived fungus, Eurotium amstelodami for the first time. The structure of questinol was determined based on the analysis of the MS and NMR spectral data as well as comparison of those data with the published data. Moreover, the anti-inflammatory effect of questinol in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was investigated. The results showed that questinol didn't exhibit cytotoxicity in LPS-stimulated RAW 264.7 cells up to 200 micrometer. Questinol could significantly inhibit NO and PGE2 production at indicated concentrations. Questinol was also found to inhibit the production of pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6. Furthermore, the western blot analysis showed that questinol suppressed the expression level of iNOS in a dose-dependent manner. However, questinol could not affect the expression of COX-2. Therefore, our study suggests a potential use of questinol might be selected as a promising agent for the prevention and therapy of inflammatory disease.
    Journal of Microbiology and Biotechnology 07/2014;
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    ABSTRACT: Severe acute respiratory syndrome (SARS), a disease that spread widely in the world during late 2002 to 2004, severely threatened public health. Although there have been no reported infections since 2004, the extremely pathogenic SARS coronavirus (SARS-CoV), as the causative agent of SARS, has recently been identified in animals, showing the potential for the re-emergence of this disease. Previous studies showed that 27 single nucleotide polymorphism (SNP) mutations among the spike (S) gene of this virus are correlated closely with the SARS pathogenicity and epidemicity. We have developed a SNP DNA microarray in order to detect and genotype these SNPs, and to obtain related information on the pathogenicity and epidemicity of a given strain. The microarray was hybridized with PCR products amplified from cDNAs obtained from different SARS-CoV strains. We were able to detect 24 SNPs and determine the type of a given strain. The hybridization profile showed that 19 samples were detected and genotyped correctly by using our microarray with 100% accuracy. Our microarray provides a novel method for the detection and epidemiological surveillance of SARS-CoV.
    Journal of Microbiology and Biotechnology 06/2014;
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    ABSTRACT: Screening of a gene library from Paenibacillus sp. PBS-2 generated in Escherichia coli led to the identification of a clone with lipolytic activity. Sequence analysis showed an open reading frame encoding a polypeptide of 378 amino acid residues with a predicted molecular weight of 42 kDa. The esterase displayed 69% and 42% identity with the putative β-lactamases from Paenibacillus sp. JDR-2 and Clostridium sp. BNL1100, respectively. The esterase contained a Ser-x-x-Lys motif that is conserved among all β-lactamases found to date. The protein PBS-2 was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at 18°C. The enzyme is a serine protein and was active against p-nitrophenyl esters of C2, C4, C8 and C10. The optimum pH and temperature for enzyme activity were pH 9.0 and 30°C, respectively. Relative activity of 55% remained at up to 5°C with an activation energy of 5.84 kcal/mol, which indicates that the enzyme is cold-adapted. Enzyme activity was inhibited by Cd(2+), Cu(2+), and Hg(2+) ions. As expected for a serine-esterase, activity was inhibited by PMSF (phenylmethylsulfonyl fluoride). It was remarkably active and stable in the presence of commercial detergents and organic solvents. This cold-adapted esterase has potential as a biocatalyst and detergent additive for use at low temperatures.
    Journal of Microbiology and Biotechnology 06/2014;
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    ABSTRACT: The specific freshwater environment of reservoirs formed by streams has not been well studied. In this paper, the bacterioplankton community in such a reservoir, the Huangqian Reservoir in eastern China, was described using culture-independent molecular methods. We found that the most dominant bacterioplankton were affiliated with Cyanobacteria, followed by Betaproteobacteria, Bacteroidetes, Gammaproteobacteria and Actinobacteria. Both bacterial abundance and diversity increased along the direction of water flow, and the 16S rRNA gene copy number in the water outlet was nearly an order of magnitude higher than that in the water inlet. Pearson correlation analyses indicated that nitrate had a significantly negative correlation with the bacterial abundance (P<0.05) and that ammonium was positively correlated with bacterial abundance (P<0.05). Interestingly, due to a remarkably negative correlation (P<0.01), the ratio of nitrate and ammonium might serve as the relative abundance of bacterioplankton. According to redundant analysis (RDA), nitrate and dissolved oxygen were the major factors influencing the bacterial communities. In addition, we attempted to determine the reasons why such a reservoir could maintain good ecological balance for a period of decades, and we found that the environmental factors and bacterial communities both played critical roles. This research will benefit our understanding of bacterial communities and their surrounding environments in freshwater ecosystems.
    Journal of Microbiology and Biotechnology 06/2014;