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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
Journal Basic Information
Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 19, Issue 12 - Dec 2009
Volume 19, Issue 11 - Nov 2009
Volume 19, Issue 10 - Oct 2009
Volume 19, Issue 9 - Sep 2009
Volume 19, Issue 8 - Aug 2009
Volume 19, Issue 7 - Jul 2009
Volume 19, Issue 6 - Jun 2009
Volume 19, Issue 5 - May 2009
Volume 19, Issue 4 - Apr 2009
Volume 19, Issue 3 - Mar 2009
Volume 19, Issue 2 - Feb 2009
Volume 19, Issue 1 - Jan 2009
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Genetic and Phenotypic Diversity of Fenitrothion-Degrading Bacteria Isolated from Soils
Kim, Kyung-Duk ; Ahn, Jae-Hyung ; Kim, Tae-Sung ; Park, Seong-Chan ; Seong, Chi-Nam ; Song, Hong-Gyu ; Ka, Jong-Ok ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 113~120
Twenty-seven fenitrothion-degrading bacteria were isolated from different soils, and their genetic and phenotypic characteristics were investigated. Analysis of the 16S rDNA sequence showed that the isolates were related to members of the genera Burkholderia, Pseudomonas, Sphingomonas, Cupriavidus, Corynebacterium, and Arthrobacter. Among the 27 isolates, 12 different chromosomal DNA fingerprinting patterns were obtained by polymerase chain reaction(PCR) amplification of repetitive extra genic palindromic(REP) sequences. The isolates were able to utilize fenitrothion as a sole source of carbon and energy, producing 3-methyl-4-nitrophenol as the intermediate metabolite during the complete degradation of fenitrothion. Twenty-two of 27 isolates were able to degrade parathion, methyl-parathion, and p-nitrophenol but only strain BS2 could degrade EPN(O-ethyl-O-p-nitrophenyl phenylphosphorothioate) as a sole source of carbon and energy for growth. Eighteen of the 27 isolates had plasmids. When analyzed with PCR amplification and dot-blotting hybridization using various specific primers targeted to the organophosphorus pesticide hydrolase genes of the previously reported isolates, none of the isolates showed positive signals, suggesting that the corresponding genes of our isolates had no significant sequence homology with those of the previously isolated organophosphate pesticide-degrading bacteria.
Identification and Functional Characterization of an afsR Homolog Regulatory Gene from Streptomyces venezuelae ATCC 15439
Maharjan, Sushila ; Oh, Tae-Jin ; Lee, Hei-Chan ; Sohng, Jae-Kyung ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 121~127
Sequencing analysis of a 5-kb DNA fragment from Streptomyces venezuelae ATCC 15439 revealed the presence of one 3.1-kb open reading frame(ORF), designated as afsR-sv. The deduced product of afsR-sv(1,056 aa) was found to have high homology with the global regulatory protein AfsR. Homology-based analysis showed that aftR-sv represents a transcriptional activator belonging to the Streptomyces antibiotic regulatory protein(SARP) family that includes an N-terminal SARP domain containing a bacterial transcriptional activation domain(BTAD), an NB-ARC domain, and a C-terminal tetratricopeptide repeat domain. Gene expression analysis by reverse transcriptase PCR(RT-PCR) demonstrated the activation of transcription of genes belonging to pikromycin production, when aftR-sv was overexpressed in S. venezuelae. Heterologous expression of the aftR-sv in different Streptomyces strains resulted in increased production of the respective antibiotics, suggesting that afsR-sv is a positive regulator of antibiotics biosynthesis.
Gene Cloning, Purification, and Characterization of a Cold-Adapted Lipase Produced by Acinetobacter baumannii BD5
Park, In-Hye ; Kim, Sun-Hee ; Lee, Yong-Seok ; Lee, Sang-Cheol ; Zhou, Yi ; Kim, Cheol-Min ; Ahn, Soon-Cheol ; Choi, Yong-Lark ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 128~135
Acinetohacter baumannii BD5 was isolated from waters of Baek-du mountain, and the lipase gene was cloned using a PCR technique. The deduced amino acid sequence of the lipase and lipase chaperone were found to encode proteins of 325 aa and 344 aa with a molecular mass of 35 kDa and 37 kDa, respectively. The lipase gene was cloned and expressed in Escherichia coli BL21(trxB) as an inclusion body, which was subsequently solubilized by urea, and then purified using Ni-affinity chromatography. After being purified, the lipase was refolded by incubation at
in the presence of a 1:10 molar ratio of lipase:chaperone. The maximal activity of the refolded lipase was observed at a temperature of
and pH 8.3 when p-NP caprate(C10) was used as a substrate; however, 28% of the activity observed at
was still remaining at
. The stability of the purified enzyme at low temperatures indicates that it is a cold-adapted enzyme. The refolded lipase was activated by
inhibited it. Additionally, 0.1% Tween 20 increased the lipase activity by 33%, but SDS and Triton X-100 inhibited the lipase activity by 40% and 70%, respectively.
Functional Expression of SAV3818, a Putative TetR-Family Transcriptional Regulatory Gene from Streptomyces avermitilis, Stimulates Antibiotic Production in Streptomyces Species
Duong, Cae Thi Phung ; Lee, Han-Na ; Choi, Si-Sun ; Lee, Sang-Yup ; Kim, Eung-Soo ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 136~139
Avermectin and its analogs are major commercial antiparasitic agents in the fields of animal health, agriculture, and human infections. Previously, comparative transcriptome analysis between the low-producer S. avermitilis ATCC31267 and the high-producer S. avermitilis ATCC31780 using a S. avermitilis whole genome chip revealed that 50 genes were overexpressed at least two-fold higher in S. avermitilis ATCC31780. To verify the biological significance of some of the transcriptomics-guided targets, five putative regulatory genes were individually cloned under the strong-and-constitutive promoter of the Streptomyces expression vector pSE34, followed by the transformation into the low-producer S. avermitilis ATCC31267. Among the putative genes tested, three regulatory genes including SAV213, SAV3818, and SAV4023 exhibited stimulatory effects on avermectin production in S. avermitilis ATCC31267. Moreover, overexpression of SAV3818 also stimulated actinorhodin production in both S. coelicolor M145 and S. lividans TK21, implying that the SAV3818, a putative TetR-family transcriptional regulator, could be a global upregulator acting in antibiotic production in Streptomyces species.
Development of an Analysis Program of Type I Polyketide Synthase Gene Clusters Using Homology Search and Profile Hidden Markov Model
Tae, Hong-Seok ; Sohng, Jae-Kyung ; Park, Kie-Jung ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 140~146
MAPSI(Management and Analysis for Polyketide Synthase Type I) has been developed to offer computational analysis methods to detect type I PKS(polyketide synthase) gene clusters in genome sequences. MAPSI provides a genome analysis component, which detects PKS gene clusters by identifying domains in proteins of a genome. MAPSI also contains databases on polyketides and genome annotation data, as well as analytic components such as new PKS assembly and domain analysis. The polyketide data and analysis component are accessible through Web interfaces and are displayed with diverse information. MAPSI, which was developed to aid researchers studying type I polyketides, provides diverse components to access and analyze polyketide information and should become a very powerful computational tool for polyketide research. The system can be extended through further studies of factors related to the biological activities of polyketides.
Gene Cloning, Expression, and Characterization of a New Carboxylesterase from Serratia sp. SES-01: Comparison with Escherichia coli BioHe Enzyme
Kwon, Min-A ; Kim, Hyun-Suk ; Oh, Joon-Young ; Song, Bong-Keun ; Song, Jae-Kwang ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 147~154
The carboxylesterase-encoding gene(bioHs) of a newly isolated strain, Serratia sp. SES-01, was cloned from the genomic DNA library by detecting formation of transparent halo around the colony on LB-tributyrin agar plates. The amino acid sequence of BioHs was highly similar to the members of the BioH enzyme family involved in the biotin biosynthetic pathway; it showed the highest similarity(91%) with that of Serratia proteamaculans. To compare BioHs with other BioH enzymes, the relatively well-known bioHe gene of E. coli was cloned with PCR. After we achieved high-level expression of soluble BioHs and BioHe through the exploration of different culture conditions, the purified BioHs and BioHe enzymes were characterized in terms of specificity, activity, and stability. BioHe was generally more robust to a change in temperature and pH and an addition of organic solvents than BioHs. The two enzymes exhibited a strong preference for carboxylesterase rather than for thioesterase and were optimal at relatively low temperatures(
) and alkaline pHs(7.5-9.0). The results in this study strongly suggested that both the BioHs and BioHe enzymes would be potential candidates for use as a carboxylesterase in many industrial applications.
Kaempferol Isolated from Nelumbo nucifera Stamens Negatively Regulates
Expression in Human Basophilic KU812F Cells
Shim, Sun-Yup ; Choi, Jae-Sue ; Byun, Dae-Seok ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 155~160
Mast cells and basophils perform important functions as pivotal effector cells in IgE-mediated allergic reactions. KU812F cells, a human basophilic cell line isolated originally from chronic myelocytic leukemia, express a high affinity receptor of IgE,
. Kaempferol was extracted and isolated from a methanolic extract of flavonoid-rich Nelumbo nucifera stamens. In the present study, the inhibitory effects of kaempferol on
expression in human basophilic KU812F cells was examined. Flow cytometric analysis revealed that
expression on the cell surface was suppressed in a concentration-dependent manner when the cells were cultured with kaempferol. Moreover, RT-PCR analysis showed that the mRNA levels for
-chains were reduced as the result of kaempferol treatment in a concentration-dependent manner. Kaempferol showed its suppressive effects on intracellular
concentration and histamine release from anti-
-chain antibody-stimulated cells in a concentration-dependent manner. These observations indicate that kaempferol may exert antiallergic effect via down regulation of
expression and degranulation.
Hydrothermal Acid Pretreatment of Chlamydomonas reinhardtii Biomass for Ethanol Production
Nguyen, Minh Thu ; Choi, Seung-Phill ; Lee, Jin-Won ; Lee, Jae-Hwa ; Sim, Sang-Jun ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 161~166
Certain microalgae have been known to use light and various carbon sources to produce carbohydrates, mainly in the form of starch. This is one of the pertinent feedstocks replacing agricultural products for the production of bioethanol by yeast. This study focuses upon dilute acid hydrothermal pretreatments at low cost and high efficiency to compete with current methods, and employs Chlamydomonas reinhardtii UTEX 90 as the feedstock. With dry cells of 5%(w/v), the algal biomass was pretreated with sulfuric acid(1-5%) under temperatures from 100 to
, from 15 to 120 min. As a result, the glucose release from the biomass was maximum at 58%(w/w) after pretreatment with 3% sulfuric acid at
for 30 min. This method enabled not only starch, but also the hydrolysis of other oligosaccharides in the algal cell in high efficiency. Arrhenius-type of model equation enabled extrapolation of some yields of glucose beyond this range. The pretreated slurry was fermented by yeast, Saccharomyces cerevisiae S288C, resulting in an ethanol yield of 29.2% from algal biomass. This study suggests that the pretreated algal biomass is a suitable feedstock for ethanol production and can have a positive impact on large-scale applied systems.
Optimization and Scale-Up of Succinic Acid Production by Mannheimia succiniciproducens LPK7
Oh, In-Jae ; Kim, Dong-Hyun ; Oh, Eun-Kyoung ; Lee, Sang-Yup ; Lee, Jin-Won ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 167~171
The effects of culture conditions on succinic acid production and its possible scale-up have been studied. Mannheimia succiniciproducens LPK7, engineered for enhanced production of succinic acid and reduced by-product secretion, was used for the experiments. Mannheimia succiniciproducens LPK7 is a knock-out strain of wild type deficient in the ldhA, pflB, and pta-ackA genes, and is derived from Mannheimia succiniciproducens MBEL55E. Process optimization of factors including optimal temperature, pH, carbon source, and nitrogen source was performed to enhance the production of succinic acid in flasks. To observe scale-up effects, batch fermentation was carried out at various working volumes. At a working volume of 7.0 l, the final succinic acid concentration and yield were 15.4g/l and 0.86g/g. This result shows similar amount of succinic acid obtained in lab-scale fermentation, and it is possible to scale up to larger fermentors without major problems.
Cloning of a Gene Encoding Dextranase from Lipomyces starkeyi and its Expression in Pichia pastoris
Kang, Hee-Kyoung ; Park, Ji-Young ; Ahn, Joon-Seob ; Kim, Seung-Heuk ; Kim, Do-Man ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 172~177
A gene(lsd1) encoding dextranase from Lipomyces starkeyi KSM22 has been previously cloned, sequenced, and expressed in Saccharomyces cerevisiae. The gene consisting of 1,824 base pairs and encoding a protein of 608 amino acids was then cloned into and secretively expressed in Pichia pastoris under the control of the AOX1 promoter. The dextranase productivity of the P. pastoris transformant(pPIC9K-LSD1, 134,000 U/I) was approximately 4.2-fold higher than that of the S. cerevisiae transformant(pYLSD1, 32,000 U/I) cultured in an 8-1 fermentor. Over 0.63 g/l of active dextranase was secreted into the medium after methanol induction. The dextranase of the P. pastoris transformant, as analyzed by SDS-PAGE and Western blotting, showed only one homogeneous band. This dextranase of the P. pastoris transformant showed a broad band near 73 kDa. Rabbit monoclonal antibodies against a synthetic LSD1 peptide mix also recognized approximately 73 kDa.
Screening and Characterization of Pro biotic Lactic Acid Bacteria Isolated from Korean Fermented Foods
Lim, Sung-Mee ; Im, Dong-Soon ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 178~186
To examine their potential as probiotics, acid and bile tolerance, antibiotics resistance, adhesion capacity to Caco-2 and HT-29, and antibacterial activity, of LAB isolated from Korean fermented foods such. as dongchimi, kimchi, Meju, and doenjang were assayed against foodborne pathogenic bacteria. DC 55, DC 136, DC 222, KC 21, KC 24, KC 34, KC 43, KC 117, MJ 54, MJ 301, SP 33, and SP 170 strains were resistant to acid and bile conditions. In particular, DC 55, DC 136, KC 24, KC 43, and MJ 301 strains were highly resistant to higher than 20
concentrations of vancomycin, streptomycin sulfate, or amoxicillin, whereas, DC 222, KC 21, KC 34, KC 117, MJ 54, and SP 33 strains were susceptible to lower than 2
concentrations of those antibiotics. The adhesion to HT-29 and Caco-2 cells varied with the strains tested in a strain-dependent manner. The highest level of adhesion was observed with DC 55, KC 21, KC 24, and MJ 301 strains, having higher than 50% of adhesion to HT-29 or Caco-2 cells. In addition, Staphylococcus aureus was the most sensitive to KC 21, showing an inhibition of about 70%, and the antibacterial activity of KC 21 against S. aureus resulted most likely from both organic acids and bacteriocin. Based on its phenotypic characteristics and utilization of various sugars, the KC 21 strain was identified as Lactobacillus plantarum.
Identification of Novel Esterase from Metagenomic Library of Yangtze River
Wu, Chao ; Sun, Baolin ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 187~193
A metagenomic library of surface-water microbes from the Yangtze River in China was constructed, and a novel esterase, designated as EstY, was isolated and characterized. EstY had 423 amino acids with an estimated molecular mass of 44 kDa and pI of 7.28. It hydrolyzed various p-nitrophenyl esters(acetate, butyrate, caprate, caprylate, laurate, myristate, and palmitate) and its best substrate was p-nitrophenyl caprate(C8). The optimum pH for EstY activity was 9.0 and the optimum temperature was
. Metal ions, such as
, strongly inhibited the activity of EstY, whereas
was required for maximal activity. Activity remained in the presence of 10% alcohol, acetone, isopropanol, and dimethyl sulfoxide, respectively. An analysis of the amino acid sequence deduced from estY revealed that it had 7 closely related lipolytic enzymes. Moreover, a sequence analysis showed that EstY, like its 7 relatives, did not belong to any known lipolytic enzyme family.
Protein in Bacillus subtilis and its Biological Functions
Wu, Huijun ; Wang, Shuai ; Qiao, Junqing ; Liu, Jun ; Zhan, Jiang ; Gao, Xuewen ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 194~203
, from rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola, is a member of the harpin group of proteins, eliciting hypersensitive cell death in non-host plants, inducing disease and insect resistance in plants, and enhancing plant growth. To express and secret the
protein in Bacillus subtilis, we constructed a recombinant expression vector pM43HF with stronger promoter P43 and signal peptide element nprB. The SDS-PAGE and Western blot analysis demonstrated the expression of the protein
in B. subtilis. The ELISA analysis determined the optimum condition for
expression in B. subtilis WBHF. The biological function analysis indicated that the protein
from B. subtilis WBHF elicits hypersensitive response(HR) and enhances the growth of tobacco. The results of RT-PCR analysis revealed that
induces expression of the pathogenesis-related genes PR-1a and PR-1b in plant defense response.
Antibacterial and Synergistic Activity of Isocryptomerin Isolated from Selaginella tamariscina
Lee, June-Young ; Choi, Yun-Jung ; Woo, Eun-Rhan ; Lee, Dong-Gun ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 204~207
We investigated novel antibacterial and synergistic activities of isocryptomerin isolated from Selaginella tamariscina. Isocryptomerin showed potent antibacterial activity against Gram-positive and Gram-negative bacterial strains including clinical isolates of antibiotic-resistant species such as methicillin-resistant Staphylococcus aureus(MRSA). Additionally, we further investigated the synergistic activity of isocryptomerin with a conventional antibiotic against MRSA. The result indicated that isocryptomerin had considerable synergistic activity in combination with cefotaxime. In summary, the present study suggests that isocryptomerin may have potential as a novel therapeutic agent for treatment of infectious diseases by not only human pathogenic bacteria but also multidrug-resistant bacteria.
Differential Expression of Nuclear Receptors in T Helper Cells
Hwang, Soo-Suk ; Kim, Young-Uk ; Lee, Won-Yong ; Lee, Gap-Ryol ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 208~214
Steroid hormones have long been known to have a profound influence on the immune system. Although the functions of the nuclear receptors in the development of T cells are fairly well studied, the differential expression of these receptors in T helper cells is poorly understood. Here, we investigated the differential expression of nuclear receptors and coregulators in Th1 and Th2 cells by genome-wide micro array analysis. The result showed that several nuclear receptors and coregulators are differentially expressed in these cells. The result was confirmed by RT-PCR. The result showed that
is highly expressed in Th2 cells. Overexpression of
in a Jurkat human T cell line induced IL4 but not IFN-
gene expression, suggesting that
plays a selective role in Th1 and Th2 differentiation. In summary, these results suggest that Th1/Th2 differentiation is influenced by differential regulation of nuclear receptors and coregulators.
Isolation and Structure Determination of a Proteasome Inhibitory Metabolite from a Culture of Scytonema hofmanni
Shim, Sang-Hee ; Chlipala, George ; Orjala, Jimmy ;
Journal of Microbiology and Biotechnology, volume 19, issue 2, 2009, Pages 215~215