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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 18, Issue 12 - Dec 2008
Volume 18, Issue 11 - Nov 2008
Volume 18, Issue 10 - Oct 2008
Volume 18, Issue 9 - Sep 2008
Volume 18, Issue 8 - Aug 2008
Volume 18, Issue 7 - Jul 2008
Volume 18, Issue 6 - Jun 2008
Volume 18, Issue 5 - May 2008
Volume 18, Issue 4 - Apr 2008
Volume 18, Issue 3 - Mar 2008
Volume 18, Issue 2 - Feb 2008
Volume 18, Issue 1 - Jan 2008
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Paenibacillus donghaensis sp. nov., a Xylan-degrading and Nitrogen-fixing Bacterium Isolated from East Sea Sediment
Choi, Jeong-Hwa ; Im, Wan-Taek ; Yoo, Jae-Soo ; Lee, Sang-Mahn ; Moon, Deok-Soo ; Kim, Hyeon-Ju ; Rhee, Sung-Keun ; Roh, Dong-Hyun ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 189~193
A Gram-positive and endospore-forming strain,
, was isolated from deep-sea sediment and identified as a member of the genus Paenibacillus on the basis of 16S rRNA gene sequence and phenotypic analyses. According to a phylogenetic analysis, the most closely related species was Paenibacillus wynnii LMG
was also facultatively anaerobic and grew optimally at
. The major cellular fatty acid was anteiso-
, and the DNA G+C content was 53.1mol%. The DNA-DNA relatedness between the isolate and Paenibacillus wynnii LMG
was 7.6%, indicating that strain
and P. wynnii belong to different species. Based on the phylogenetic, phenotypic, and chemotaxonomic characteristics, strain
would appear to belong to a novel species, for which the name Paenibacillus donghaensis sp. novo is proposed (type strain=KCTC
Characterization of Cytophaga-Flavobacteria Community Structure in the Bering Sea by Cluster-specific 16S rRNA Gene Amplification Analysis
Chen, Xihan ; Zeng, Yonghui ; Jiao, Nianzhi ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 194~198
A newly designed Cytophaga-Flavobacteria-specific 16S rRNA gene primer pair was employed to investigate the CF community structure in the Bering Sea, revealing a previously unknown and unexpected high CF diversity in this high latitude cold sea. In total, 56 clones were sequenced and 50 unique CF 16 rRNA gene fragments were obtained, clustering into 16 CF subgroups, including nine cosmopolitan subgroups, five psychrophilic subgroups, and two putatively autochthonous subgroups. The majority of sequences (82%) were closely related to uncultured CF species and could not be classified into known CF genera, indicating the presence of a large number of so-far uncultivated CF species in the Bering Sea.
Genetic and Physiological Characterization of Oxytetracycline-Resistant Bacteria from Giant Prawn Farms
Heepngoen, Pimpak ; Sajjaphan, Kannika ; Ferguson, John A. ; Sadowsky, Michael J. ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 199~206
Four hundred and thirteen oxytetracycline-resistant bacteria were recovered from six freshwater giant prawn farms with a history of oxytetracycline use. Most oxytetracycline-resistant isolates were Gram-negative bacteria. Six groups of oxytetracycline-resistant bacteria were classified using cluster analysis based on a comparison of levels of oxytetracycline resistance. Complex fingerprint patterns were obtained for 71 isolates studied. In general, the band patterns of isolates from different ponds were very similar, and the data indicated that the isolates were closely related. The exploration for cross-resistance found that most of the 71 oxytetracycline-resistant isolates were also resistant to tetracycline and chlortetracycline, but had a relatively low resistance to doxycycline. Many isolates showed higher chlortetracycline resistance than oxytetracycline resistance. Additionally, the oxytetracycline-resistant isolates were examined for the presence of tetracycline resistance (tet) genes. Fifty percent of the isolates carried one of the 14 known tet genes examined. The most common determinants were TetA and TetD. However, TetB, TetC, TetE, TetK, TetL, and TetM were also found with various frequencies.
Molecular Analysis of Bacterial Community Structures in Paddy Soils for Environmental Risk Assessment with Two Varieties of Genetically Modified Rice, Iksan 483 and Milyang 204
Kim, Min-Cheol ; Ahn, Jae-Hyung ; Shin, Hye-Chul ; Kim, Tae-Sung ; Ryu, Tae-Hun ; Kim, Dong-Hern ; Song, Hong-Gyu ; Lee, Geon-Hyoung ; Ka, Jong-Ok ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 207~218
The impacts of planted transgenic rice varieties on bacterial communities in paddy soils were monitored using both cultivation and molecular methods. The rice field plot consisted of eighteen subplots planted with two genetically modified (GM) rice and four non-GM rice plants in three replicates. Analysis with denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes revealed that the bacterial community structures were quite similar to each other in a given month, suggesting that there were no significant differences in bacterial communities between GM and non-GM rice soils. The bacterial community structures appeared to be generally stable with the seasons, as shown by a slight variation of microbial population levels and DGGE banding patterns over the year. Comparison analysis of 16S rDNA clone libraries constructed from soil bacterial DNA showed that there were no significant differences between GM and non-GM soil libraries but revealed seasonal differences of phyla distribution between August and December. The composition profile of phospholipid fatty acids (PLFA) between GM and non-GM soils also was not significantly different to each other. When soil DNAs were analyzed with PCR by using primers for the bar gene, which was introduced into GM rice, positive DNA bands were found in October and December soils. However, no bar gene sequence was detected in PCR analysis with DNAs extracted from both cultured and uncultured soil bacterial fractions. The result of this study suggested that, in spite of seasonal variations of bacterial communities and persistence of the bar gene, the bacterial communities of the experimental rice field were not significantly affected by cultivation of GM rice varieties.
Genes of Rhodobacter sphaeroides 2.4.1 Regulated by Innate Quorum-Sensing Signal, 7,8-cis-N-(Tetradecenoyl) Homoserine Lactone
Hwang, Won ; Lee, Ko-Eun ; Lee, Jeong-Kug ; Park, Byoung-Chul ; Kim, Kun-Soo ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 219~227
The free-living photoheterotrophic Gram-negative bacterium Rhodobacter sphaeroides possesses a quorum-sensing (QS) regulatory system mediated by CerR-CerI, a member of the LuxR-LuxI family. To identify the genes affected by the regulatory system, random lacZ fusions were generated in the genome of R. sphaeroides strain 2.4.1 using a promoter-trapping vector, pSG2. About 20,000 clones were screened and 23 showed a significantly different level of
-gal activities upon the addition of synthetic 7,8-cis-N-tetradecenoyl-homoserine lactone (RAI). Among these 23 clones, the clone showing the highest level of induction was selected for further study, where about a ten-fold increase of
-gal activity was exhibited in the presence of RAI and induction was shown to be required for cerR. In this clone, the lacZ reporter was inserted in a putative gene that exhibited a low homology with catD. A genetic analysis showed that the expression of the catD homolog was initiated from a promoter of another gene present upstream of the catD. This upstream gene showed a strong homology with luxR and hence was named qsrR (quorum-sensing regulation regulator). A comparison of the total protein expression profiles for the wild-type cells and qsrR-null mutant cells using two-dimensional gel electrophoresis and a MALDI-TOF analysis allowed the identification of sets of genes modulated by the luxR homolog.
Effects of Chaperones on mRNA Stability and Gene Expression in Escherichia coli
Yoon, Hyun-Jin ; Hong, Ji-Young ; Ryu, Sang-Ryeol ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 228~233
Effects of chaperones on mRNA stability and gene expression were studied in order to develop an efficient Escherichia coli expression system that can maximize gene expression. The stability of mRNA was modulated by introducing various secondary structures at the 5'-end of mRNA. Four vector systems providing different 5'-end structures were constructed, and genes encoding GFPuv and endoxylanase were cloned into the four vector systems. Primer extension assay revealed different mRNA half-lives depending on the 5'-end secondary structures of mRNA. In addition to the stem-loop structure at the 5'-end of mRNA, coexpression of dnaK-dnaJ-grpE or groEL-groES, representative heat-shock genes in E. coli, increased the mRNA stability and the level of gene expression further, even though the degree of stabilization was varied. Our work suggests that some of the heat-shock proteins can function as mRNA stabilizers as well s protein chaperones.
Agrobacterium tumefaciens-mediated Transformation in Colletotrichum falcatum and C. acutatum
Maruthachalam, Karunakaran ; Nair, Vijayan ; Rho, Hee-Sool ; Choi, Jae-Hyuk ; Kim, Soon-Ok ; Lee, Yong-Hwan ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 234~241
Agrobacterum tumefaciens-mediated transformation (ATMT) is becoming an effective system as an insertional mutagenesis tool in filamentous fungi. We developed and optimized ATMT for two Colletotrichum species, C. falcatum and C. acutatum, which are the causal agents of sugarcane red rot and pepper anthracnose, respectively. A. tumefaciens strain SK1044, carrying a hygromycin phosphotransferase gene (hph) and a green fluorescent protein (GFP) gene, was used to transform the conidia of these two Colletotrichum species. Transformation efficiency was correlated with co-cultivation time and bacterial cell concentration and was higher in C. falcatum than in C. acutatum. Southern blot analysis indicated that about 65% of the transformants had a single copy of the T-DNA in both C. falcatum and C. acutatum and that T-DNA integrated randomly in both fungal genomes. T-DNA insertions were identified in transformants through thermal asymmetrical interlaced PCR (TAIL-PCR) followed by sequencing. Our results suggested that ATMT can be used as a molecular tool to identify and characterize pathogenicity-related genes in these two economically important Colletotrichum species.
Roles of Zinc-responsive Transcription Factor Csr1 in Filamentous Growth of the Pathogenic Yeast Candida albicans
Kim, Min-Jeong ; Kil, Min-Kwang ; Jung, Jong-Hwan ; Kim, Jin-Mi ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 242~247
In the fungal pathogen Candida albicans, the yeast-to-hyphal transition occurs in response to a broad range of environmental stimuli and is considered to be a major virulence factor. To address whether the zinc homeostasis affects the growth or pathogenicity of C. albicans, we functionally characterized the zinc-finger protein Csr1 during filamentation. The deduced amino acid sequence of Csr1 showed a 49% similarity to the zinc-specific transcription factor, Zap1 of Saccharomyces cerevisiae. Sequential disruptions of CSR1 were carried out in diploid C. albicans. The csr1/csr1 mutant strain showed severe growth defects under zinc-limited growth conditions and the filamentation defect under hypha-inducing media. The colony morphology and the germ-tube formation were significantly affected by the csr1 mutation. The expression of the hyphae-specific gene HWP1 was also impaired in csr1/csr1 cells. The C. albicans homologs of ZRTl and ZRT2, which are zinc-transporter genes in S. cerevisiae, were isolated. High-copy number plasmids of these genes suppressed the filamentation defect of the csr1/csr1 mutant strain. We propose that the filamentation phenotype of C. albicans is closely associated with the zinc homeostasis in the cells and that Csr1 plays a critical role in this regulation.
Proteomic Analysis of Fructophilic Properties of Osmotolerant Candida magnoliae
Yu, Ji-Hee ; Lee, Dae-Hee ; Park, Yong-Cheol ; Lee, Mi-Gi ; Kim, Dae-Ok ; Ryu, Yeon-Woo ; Seo, Jin-Ho ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 248~254
Candida magnoliae, an osmotolerant and erythritol producing yeast, prefers D-fructose to D-glucose as carbon sources. For the investigation of the fructophilic characteristics with respect to sugar transportation, a sequential extraction method using various detergents and ultracentrifugation was developed to isolate cellular membrane proteins in C. magnoliae. Immunoblot analysis with the Pma1 antibody and two-dimensional electrophoresis analysis coupled with MS showed that the fraction II was enriched with membrane proteins. Eighteen proteins out of 36 spots were identified as membrane or membrane-associated proteins involved in sugar uptake, stress response, carbon metabolism, and so on. Among them, three proteins were significantly upregulated under the fructose supplying conditions. The hexose transporter was highly homologous to Ght6p in Schizosaccharomyces pombe, which was known as a predominant transporter for the fructose uptake of S. pombe because it exhibited higher affinity to D-fructose than D-glucose. The physicochemical properties of the ATP-binding cassette transporter and inorganic transporter explained their direct or indirect associations with the fructophilic behavior of C. magnoliae. The identification and characterization of membrane proteins involved in sugar uptake might contribute to the elucidation of the selective utilization of fructose to glucose by C. magnoliae at a molecular level.
Differential Induction of Protein Expression and Benzophenanthridine Alkaloid Accumulation in Eschscholtzia californica Suspension Cultures by Methyl Jasmonate and Yeast Extract
Cho, Hwa-Young ; Rhee, Hong-Soon ; H. Yoon, Sung-Yong ; Park, Jong-Moon ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 255~262
Methyl jasmonate (MJ) and yeast extract (YE) induce protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cell cultures. One hundred
MJ primarily induced dihydrosanguinarine
; 0.2g/l YE induced sanguinarine
and an unknown compound. These results occur because dihydrobenzophenanthridine oxidase (DHBO) is induced by YE and not by MJ. YE and chitin (CHI) had similar effects on sanguinarine production and DHBO expression. Differential induction of secondary metabolites was shown in E. californica suspension cultures and the expression of proteins confirmed the metabolite results. Furthermore, treatment by various oligosaccharides helped us to understand the elicitation effect of YE in signal transduction pathways.
Genome-wide Drug-induced Haploinsufficiency Screening of Fission Yeast for Identification of Hydrazinocurcumin Targets
Baek, Seung-Tae ; Kim, Dong-Uk ; Han, Sang-Jo ; Woo, Im-Sun ; Nam, Mi-Young ; Kim, Li-La ; Heo, Kyung-Sun ; Lee, Hye-Mi ; Hwang, Hye-Rim ; Choi, Shin-Jung ; Won, Mi-Sun ; Lee, Min-Ho ; Park, Song-Kyu ; Lee, Sung-Hou ; Kwon, Ho-Jeong ; Maeng, Pil-Jae ; Park, Hee-Moon ; Park, Young-Woo ; Kim, Dong-Sup ; Hoe, Kwang-Lae ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 263~269
Hydrazinocurcumin (HC), a synthetic derivative of curcumin, has been reported to inhibit angiogenesis via unknown mechanisms. Understanding the molecular mechanisms of the drug's action is important for the development of improved compounds with better pharmacological properties. A genome-wide drug-induced haploinsufficiency screening of fission yeast gene deletion mutants has been applied to identify drug targets of HC. As a first step, the 50% inhibition concentration
of HC was determined to be
. The initial screening of 4,158 mutants in 384-well plates using robotics was performed at concentrations of 2, 3, and
. A second screening was performed to detect sensitivity to HC on the plates. The first screening revealed 178 candidates, and the second screening resulted in 13 candidates, following the elimination of 165 false positives. Final filtering of the condition-dependent haploinsufficient genes gave eight target genes. Analysis of the specific targets of HC has shown that they are related to septum formation and the general transcription processes, which may be related to histone acetyltransferase. The target mutants showed 65% growth inhibition in response to HC compared with wild-type controls, as shown by liquid culture assay.
Gpx3-dependent Responses Against Oxidative Stress in Saccharomyces cerevisiae
Kho, Chang-Won ; Lee, Phil-Young ; Bae, Kwang-Hee ; Kang, Sung-Hyun ; Cho, Sa-Yeon ; Lee, Do-Hee ; Sun, Choong-Hyun ; Yi, Gwan-Su ; Park, Byoung-Chul ; Park, Sung-Goo ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 270~282
The yeast Saccharomyces cerevisiae has defense mechanisms identical to higher eukaryotes. It offers the potential for genome-wide experimental approaches owing to its smaller genome size and the availability of the complete sequence. It therefore represents an ideal eukaryotic model for studying cellular redox control and oxidative stress responses. S. cerevisiae Yap1 is a well-known transcription factor that is required for
-dependent stress responses. Yap1 is involved in various signaling pathways in an oxidative stress response. The Gpx3 (Orp1/PHGpx3) protein is one of the factors related to these signaling pathways. It plays the role of a transducer that transfers the hydroperoxide signal to Yap1. In this study, using extensive proteomic and bioinformatics analyses, the function of the Gpx3 protein in an adaptive response against oxidative stress was investigated in wild-type, gpx3-deletion mutant, and gpx3-deletion mutant overexpressing Gpx3 protein strains. We identified 30 proteins that are related to the Gpx3-dependent oxidative stress responses and 17 proteins that are changed in a Gpx3-dependent manner regardless of oxidative stress. As expected,
-responsive Gpx3-dependent proteins include a number of antioxidants related with cell rescue and defense. In addition, they contain a variety of proteins related to energy and carbohydrate metabolism, transcription, and protein fate. Based upon the experimental results, it is suggested that Gpx3-dependent stress adaptive response includes the regulation of genes related to the capacity to detoxify oxidants and repair oxidative stress-induced damages affected by Yap1 as well as metabolism and protein fate independent from Yap1.
Crystallization and Preliminary X-Ray Diffraction Analysis of 5,10-Methylenetetrahydrofolate Dehydrogenase/Cyclohydrolase from Thermoplasma acidophilum DSM 1728
Kim, Jae-Hee ; Sung, Min-Woo ; Lee, Eun-Hye ; Nam, Ki-Hyun ; Hwang, Kwang-Yeon ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 283~286
The methylenetetrahydrofolate dehydrogenase/cyclohydrolase (MTHFDC) from the thermoacidophilic archaeon Thermoplasma acidophilum is a 30.6kDa molecular-mass enzyme that sequentially catalyzes the conversion of formyltetrahydrofollate to methylenetetrahydrofolate, with a preference for NADP as a cofactor, rather than NAD. In order to elucidate the functional and structural features of MTHFDC from archaeons at a molecular level, it was overexpressed in Escherichia coli and crystallized in the presence of its cofactor, NADP, at 295K using polyethylene glycol (PEG) 4000 as a precipitant. The crystal is a member of the monoclinic space group
, with the following unit cell parameters:
, and diffracts to a resolution of at least
at the synchrotron. Assuming a dimer in the crystallographic asymmetric unit, the calculated Matthews parameter
and the solvent content was 49.7%.
Mutational Analysis of Thermus caldophilus GK24
-Glycosidase: Role of His119 in Substrate Binding and Enzyme Activity
Oh, Eun-Joo ; Lee, Yoon-Jin ; Choi, Jeong-Jin ; Seo, Moo-Seok ; Lee, Mi-Sun ; Kim, Gun-A ; Kwon, Suk-Tae ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 287~294
Three amino acid residues (His119, Glu164, and Glu338) in the active site of Thermus caldophilus GK24
-glycosidase), a family 1 glycosyl hydrolase, were mutated by site-directed mutagenesis. To verify the key catalytic residues, Glu164 and Glu338 were changed to Gly and Gln, respectively. The E164G mutation resulted in drastic reductions of both
-glucosidase activities, and the E338Q mutation caused complete loss of activity, confirming that the two residues are essential for the reaction process of glycosidic linkage hydrolysis. To investigate the role of His119 in substrate binding and enzyme activity, the residue was substituted with Gly. The H119G mutant showed 53-fold reduced activity on 5mM p-nitrophenyl
-D-galactopyranoside, when compared with the wild type; however, both the wild-type and mutant enzymes showed similar activity on 5mM p-nitrophenyl
. Kinetic analysis with p-nitrophenyl
-D-galactopyranoside revealed that the
value of the H119G mutant was 76.3-fold lower than that of the wild type, but the
of the mutant was 15.3-fold higher than that of the wild type owing to the much lower affinity of the mutant. Thus, the catalytic efficiency
of the mutant decreased to 0.08% to that of the wild type. The
value of the H119G mutant for p-nitrophenyl
-D-glucopyranoside was 5.l-fold higher than that of the wild type, but the catalytic efficiency of the mutant was 2.5% of that of the wild type. The H119G mutation gave rise to changes in optima pH (from 5.5-6.5 to 5.5) and temperature (from
). This difference of temperature optima originated in the decrease of H119G's thermostability. These results indicate that His119 is a crucial residue in
-glucosidase activities and also influences the enzyme's substrate binding affinity and thermostability.
Overexpression, Purification, and Preliminary X-ray Crystallographic Analysis of Human Brain-Type Creatine Kinase
Bong, Seung-Min ; Moon, Jin-Ho ; Jang, Eun-Hyuk ; Lee, Ki-Seog ; Chi, Young-Min ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 295~298
Creatine kinase (CK; E.C. 184.108.40.206) is an important enzyme that catalyzes the reversible transfer of a phosphoryl group from ATP to creatine in energy homeostasis. The brain-type cytosolic isoform of creatine kinase (BB-CK), which is found mainly in the brain and retina, is a key enzyme in brain energy metabolism, because high-energy phosphates are transfered through the creatine kinase/phosphocreatine shuttle system. The recombinant human BB-CK protein was overexpressed as a soluble form in Escherichia coli and crystallized at
using PEG 4000 as a precipitant. Native X-ray diffraction data were collected to
resolution using synchrotron radiation. The crystals belonged to the tetragonal space group
, with cell parameters of a=b=97.963,
. The asymmetric unit contained two molecules of CK, giving a crystal volume per protein mass
and a solvent content of 31.6%.
Expression and Purification of Intact and Functional Soybean (Glycine max) Seed Ferritin Complex in Escherichia coli
Dong, Xiangbai ; Tang, Bo ; Li, Jie ; Xu, Qian ; Fang, Shentong ; Hua, Zichun ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 299~307
Soybean seed ferritin is essential for human iron supplementation and iron deficiency anemia prevention because it contains abundant bioavailable iron and is frequently consumed in the human diet. However, it is poorly understood in regards its several properties, such as iron mineralization, subunit assembly, and protein folding. To address these issues, we decided to prepare the soybean seed ferritin complex via a recombinant DNA approach. In this paper, we report a rapid and simple Escherichia coli expression system to produce the soybean seed ferritin complex. In this system, two subunits of soybean seed ferritin, H-2 and H-1, were encoded in a single plasmid, and optimal expression was achieved by additionally coexpressing a team of molecular chaperones, trigger factor and GroEL-GroES. The His-tagged ferritin complex was purified by
affinity chromatography, and an intact ferritin complex was obtained following His-tagged enterokinase (His-EK) digestion. The purified ferritin complex synthesized in E. coli demonstrated some reported features of its native counterpart from soybean seed, including an apparent molecular weight, multimeric assembly, and iron uptake activity. We believe that the strategy described in this paper may be of general utility in producing other recombinant plant ferritins built up from two types of subunits.
Lactic Acid Bacterial Fermentation Increases the Antiallergic Effects of Ixeris dentata
Park, Eun-Kyung ; Sung, Jin-Hee ; Trinh, Hien-Trung ; Bae, Eun-Ah ; Yun, Hyung-Kwon ; Hong, Seong-Sig ; Kim, Dong-Hyun ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 308~313
Ixeris dentata (ID, family Asteraceae), called Seumbakuy in Korea, was fermented with lactic acid bacteria (LAB) and their antiallergic activities were investigated. Fermentation of ID with Bifidobacterium breve or Lactobacillus acidophilus increased its inhibition of degranulation in RBL-2H3 cells induced by the IgE-antigen complex. Oral administration of these extracts to mice inhibited the passive cutaneous anaphylaxis (PCA) reaction induced by the IgE-antigen complex and scratching behaviors induced by compound 48/80. The fermented ID more potently inhibited the PCA reaction and scratching behaviors than the non-fermented one. These extracts also inhibited mRNA expression of TNF-
and IL-4, as well as NF-
activation in RBL-2H3 cells induced by the IgE-antigen complex. These findings suggest that LAB fermentation improves ID-mediated inhibition of IgE-induced allergic diseases such as rhinitis and asthma, and that ID works by inhibiting degranulation and NF-
activation in mast cells and basophils.
Acaricidal Activity and Function of Mite Indicator Using Plumbagin and Its Derivatives Isolated from Diospyros kaki Thunb. Roots (Ebenaceae)
Lee, Chi-Hoon ; Lee, Hoi-Seon ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 314~321
Acaricidal effects of materials derived from Diospyros kaki roots against Dermatophagoides farinae and D. pteronyssinus were assessed using impregnated fabric disk bioassay and compared with that of the commercial benzyl benzoate. The observed responses varied according to dosage and mite species. The
values of the chloroform extract of Diospyros kaki roots were 1.66 and
against D. farinae and D. pteronyssinus. The chloroform extract of Diospyros kaki roots was approximately 15.2 more toxic than benzyl benzoate against D. farinae, and 7.6 times more toxic against D. pteronyssinus. Purification of the biologically active constituent from D. kaki roots was done by using silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by GC-MS,
COSY-NMR, and DEPT-NMR spectra, and identified as plumbagin. The acaricidal activity of plumbagin and its derivatives (naphthazarin, dichlon, 2,3-dibromo-1,4-naphthoquinone, and 2-bromo-1,4-naphthoquinone) was examined. On the basis of
values, the most toxic compound against D. farinae was naphthazarin
followed by plumbagin
, and benzyl benzoate
. Additionally, the skin color of the dust mites was changed from colorless-transparent to dark brown-black by the treatment of plumbagin. Similar results have been exhibited in its derivatives (naphthazarin, dichlon, and 2-bromo-1,4-naphthoquinone). In contrast, little or no discoloration was observed for benzyl benzoate. From this point of view, plumbagin and its derivatives can be very useful for the potential control agents, lead compounds, and indicator of house dust mites.
Production of 1,5-Dihydroxy-3-Methoxy-7-Methylanthracene-9,10-Dione by Submerged Culture of Shiraia bambusicola
Cai, Yujie ; Ding, Yanrui ; Tao, Guanjun ; Liao, Xiangru ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 322~327
1,5-Dihydroxy-3-methoxy-7-methylanthracene-9,10-dione (shiraiarin) is a kind of antitumor and antibacterial anthraquinone, and was produced for the first time from the submerged fermentation of Shiraia bambusicola, as confirmed by ESI-MS and NMR. The production of shiraiarin was significantly influenced when varying the carbon source, and a high amount of shiraiarin was only achieved when using lactose. The production of shiraiarin was also stimulated when using
as the nitrogen source, whereas other nitrogen sources inhibited its production. Shiraiarin was formed during the stationary phase with a pH value higher than 8. The production of shiraiarin was inhibited by sporulation.
Selection and Target-Site Mapping of Peptides Inhibiting HCV NS5B Polymerase Using Phage Display
Kim, Min-Soo ; Park, Chan-Hee ; Lee, Jong-Ho ; Myung, Hee-Joon ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 328~333
A series of pep tides binding to the HCV NS5B polymerase was selected from phage display peptide libraries. A conserved motif of Ser-Arg-X-Arg/Leu was identified among the selected peptides, and Pep2 (Trp-Ser-Arg-Pro-Arg-Ser-Leu) was chosen for further characterization. The binding of Pep2 to HCV NS5B in vivo was shown by a yeast two-hybrid assay and by subcellular colocalization analysis using immunofluorescence confocal microscopy. The in vitro interaction was also confirmed by GST pulldown assay. The replication of the HCV 1b subgenomic replicon was efficiently inhibited by the presence of the peptide. By using a subtractive biopanning against Pep2, the binding site of the peptide was mapped at the pocket of Pro388 to Pro391 in the thumb subdomain of the polymerase. A yeast two-hybrid analysis using Pro388Ala and Pro391Ala mutants of NS5B confirmed the binding.
Control of Acetate Production Rate in Escherichia coli by Regulating Expression of Single-Copy pta Using
in Multicopy Plasmid
Lee, Sun-Gu ; Liao, James C ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 334~337
A tightly regulated gene expression system composed of a single-copy target gene under the control of a lac promoter derivative and lacI gene in a multicopy plasmid is proposed, and its ability to control the flux of a metabolic pathway is demonstrated. A model system to control the flux of acetyl-CoA to acetyl phosphate was constructed by integrating pta, a gene encoding phosphotransacetylase, under a tac promoter into the chromosome of E. coli with a pta-negative background and transforming a multicopy plasmid containing the
gene into the strain. The production rate of acetate was shown to be tightly controlled when varying the concentration of the inducer (IPTG) in he model system.
Screening of Lactobacilli Derived from Chicken Feces and Partial Characterization of Lactobacillus acidophilus A12 as Animal Probiotics
Lee, Na-Kyoung ; Yun, Cheol-Won ; Kim, Seung-Wook ; Chang, Hyo-Ihl ; Kang, Chang-Won ; Paik, Hyun-Dong ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 338~342
This study was performed to screen and select Lactobacillus strains from chicken feces for probiotic use in animals. Of these strains, strain AU had the highest immunostimulatory effect. Therefore, strain A12 was characterized as a potential probiotic. Strain A12 was tentatively identified as Lactobacillus acidophilus A12, using the API 50 CHL kit based on a 99.9% homology. L. acidophilus A12 was highly resistant to artificial gastric juice (pH 2.5) and bile acid (oxgall). Based on results from the API ZYM kit, leucine arylamidase, crystine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase,
-glucosidase, and N-acetyl-
-glucosamidase were produced by strain A12. L. acidophilus A12 showed resistance to several antibiotics (nisin, gentamicin, and erythromycin). The amount of interleukin
concentrated supernatant from L. acidophilus A12 was approximately 156pg/ml. With regard to antioxidant activity, L. acidophilus A12 supernatant showed 60.6% DPPH radical scavenging activity. These results demonstrate the potential use of L. acidophilus A12 as health-promoting probiotics.
Microbial Biodegradation and Toxicity of Vinclozolin and its Toxic Metabolite 3,5-Dichloroaniline
Lee, Jung-Bok ; Sohn, Ho-Yong ; Shin, Kee-Sun ; Kim, Jong-Sik ; Jo, Min-Sub ; Jeon, Chun-Pyo ; Jang, Jong-Ok ; Kim, Jang-Eok ; Kwon, Gi-Seok ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 343~349
Vinclozolin, an endocrine disrupting chemical, is a chlorinated fungicide widely used to control fungal diseases. However, its metabolite 3,5-dichloroaniline is more toxic and persistent than the parent vinclozolin. For the biodegradation of vinclozolin, vinclozolin- and/or 3,5-dichloroaniline-degrading bacteria were isolated from pesticide-polluted agriculture soil. Among the isolated bacteria, a Rhodococcus sp. was identified from a 16S rDNA sequence analysis and named Rhodococcus sp. T1-1. The degradation ratios for vinclozolin or 3,5-dichloroaniline in a minimal medium containing vinclozolin
were 90% and 84.1%, respectively. Moreover, Rhodococcus sp. T1-1 also showed an effective capability to biodegrade dichloroaniline isomers on enrichment cultures in which they were contained. Therefore, these results suggest that Rhodococcus sp. T1-1 can bioremediate vinclozolin as well as 3,5-dichloroaniline.
Prevalence of Human Papillomavirus and Herpes Simplex Virus Type 2 Infection in Korean Commercial Sex Workers
Yun, Hae-Sun ; Park, Jeong-Joo ; Choi, In-Kyung ; Kee, Mee-Kyung ; Choi, Byeong-Sun ; Kim, Sung-Soon ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 350~354
In order to investigate the prevalence of sexually transmitted viruses such as human papillomavirus (HPV) and herpes simplex virus (HSV) in Korean commercial sex workers (CSWs), we selected 188 CSWs (age range 20-44 years, median age 24 years) who regularly visited one public health center in Seoul, Korea. HPV genotypes were analyzed by using a HPV DNA Chip, and an enzyme-linked immunosorbent assay (ELISA) was used to detect type-specific IgG against HSV2 antibody identifying seropositivity for HSV2 infection. Polymerase chain reaction (PCR) was performed with specific primers to detect HPV and HSV1/2 in cervical swabs from the CSWs. The prevalence of HPV infection was 83.5% in 188 cervical swab specimens and the main high-risk HPV genotypes were HPV16, 18, 56, and 58. The principal low-risk HPV genotypes were HPV6 and 11. The prevalence of HSV1/2 DNA was 13.8% and HSV2 seroprevalence was 86.2%. These results suggest that high frequencies of HPV and HSV2 infection might contribute to the rapid spread of STD viruses in CSWs in Korea. Additionally, an understanding of why high-risk HPV genotypes are so prevalent could provide guidelines for prophylactic vaccine development in Korea.
Molecular Mechanism of Macrophage Activation by Exopolysaccharides from Liquid Culture of Lentinus edodes
Lee, Ji-Yeon ; Kim, Joo-Young ; Lee, Yong-Gyu ; Rhee, Man-Hee ; Hong, Eock-Ki ; Cho, Jae-Youl ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 355~364
Mushrooms are regarded as one of the well-known foods and biopharmaceutical materials with a great deal of interest.
-Glucan is the major component of mushrooms that displays various biological activities such as antidiabetic, anticancer, and antihyperlipidemic effects. In this study, we explored the molecular mechanism of its immunostimulatory potency in immune responses of macrophages, using exopolysaccharides prepared from liquid culture of Lentinus edodes. We found that fraction II (F-II), with large molecular weight protein polysaccharides, is able to strongly upregulate the phenotypic functions of macrophages such as phagocytic uptake, ROS/NO production, cytokine expression, and morphological changes. F-II triggered the nuclear translocation of NF-
and activated its upstream signaling cascades such as PI3K/Akt and MAPK pathways, as assessed by their phosphorylation levels. The function-blocking antibodies to dectin-1 and TLR-2, but not CR3, markedly suppressed F-II-mediated NO production. Therefore, our data suggest that mushroom-derived
-glucan may exert its immunostimulating potency via activation of multiple signaling pathways.
Channel Activity by Protein Tyrosine Phosphorylation
Huh, Sung-Un ; Kang, Ho-Won ; Park, Jin-Yong ; Lee, Jung-Ha ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 365~368
Calcium entry through
channels plays essential roles for various physiological events including thalamic oscillation, muscle contraction, hormone secretion, and sperm acrosomal reaction. In this study, we examined how protein tyrosine phosphatases or protein tyrosine kinases affect
channels reconstituted in Xenopus oocytes. We found that
channel activity was reduced by 25% in response to phenylarsine oxide (tyrosine phosphatase inhibitor), whereas it was augmented by 19% in response to Tyr A47 or herbimycin A (tyrosine kinase inhibitors). However, other biophysical properties of
currents were not significantly changed by the drugs. These results imply that
channel activity is capable of being increased by activation of tyrosine phosphatases, but is decreased by activation of tyrosine kinases.
Radioprotective Effect of Cyclo(L-Phenylalanyl-L-Prolyl) on Irradiated Rat Lung
Lee, Keyong-Ho ; Rhee, Ki-Hyeong ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 369~376
In the present study, we investigated the radioprotective effect of cyclo(L-phenylalanyl-L-prolyl) on irradiated rat lungs to determine its potential as a radioprotective agent. We found that early lung damage induced by irradiation was reduced by treatment with 40mg/kg of cyclo(L-phenylalanyl-L-prolyl) in the latent and early pneumonitis phases. Expression of
at 2 and TGF-
at 8 weeks post-irradiation was decreased in animals that received both radiation and cyclo(L-phenylalanyl-L-prolyl) compared with animals that received radiation alone. Evidence indicated that the proinflammatory cytokine TNF-
and the fibrogenic cytokine TGF-
likely play a role in the radioprotective effect of cyclo(L-phenylalanyl-L-prolyl). However, besides TNF-
expressions, the precise mechanism by which cyclo(L-phenylalanyl-L-prolyl) ameliorates the induced radiation damage is not clear.
Interleukin-2 Promotes Angiogenesis by Activation of Akt and Increase of ROS
Bae, Jin-Hee ; Park, Deok-Bum ; Lee, Yun-Sil ; Jeoung, Doo-Il ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 377~382
Interleukin-2 plays a significant role in T cell proliferation. Here, we report the role of IL-2 in angiogenesis. IL-2 increased the ROS level and phosphorylation of Akt in human umbilical vein endothelial cells (HUVECs). IL-2 increased angiogenesis in an animal model and tube formation in HUVECs. The effect of IL-2 on angiogenesis and tube formation was mediated by ROS and Akt. This is the first report that IL-2 promotes angiogenesis.
Expression and Characterization of Human N-Acetylglucosaminyltransferases and
2,3-Sialyltransferase in Insect Cells for In Vitro Glycosylation of Recombinant Erythropoietin
Kim, Na-Young ; Kim, Hyung-Gu ; Kim, Yang-Hyun ; Chung, In-Sik ; Yang, Jai-Myung ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 383~391
The glycans linked to the insect cell-derived glycoproteins are known to differ from those expressed in mammalian cells, partly because of the low level or lack of glycosyltransferase activities. GnT II, GnT IV, GnT V, and ST3Gal IV, which play important roles in the synthesis of tetraantennarytype complex glycan structures in mammalian cells, were overexpressed in Trichoplusia ni cells by using a baculovirus expression vector. The glycosyltransferases, expressed as a fusion form with the IgG-binding domain, were secreted into the culture media and purified using IgG sepharose resin. The enzyme assay, performed using a pyridylaminated-sugar chain as an acceptor, indicated that the purified glycosyltransferases retained their enzyme activities. Human erythropoietin expressed in T. ni cells (rhEPO) was subjected to in vitro glycosylation by using recombinant glycosyltransferases and was converted into complex-type glycan with terminal sialic acid. The presence of Nacetylglucosamine, galactose, and sialic acid on the rhEPO moiety was detected by a lectin blot analysis, and the addition of galactose and sialic acid to rhEPO was confirmed by autoradiography using
as donors. The in vitro glycosylated rhEPO was injected into mice, and the number of reticulocytes among the ed blood cells was counted using FACS. A significant increase in the number of reticulocytes was not observed in the mice injected with in vitro glycosylated rhEPO as compared with those injected with rhEPO.
Regulation of NO from Endothelial Cells by the Decrease of Cellular cAMP Under Arsenite Exposure
Lee, Soo-Youn ; Min, Ji-Ho ;
Journal of Microbiology and Biotechnology, volume 18, issue 2, 2008, Pages 392~395
In an attempt to delineate the direct effect of arsenite-induced endothelial dysfunction on nitric oxide (NO) production, confluent bovine aortic endothelial cells (BAEC) were incubated with arsenite, and endothelial NO synthase expression and NO production were measured. Exposure of arsenite decreased NO production for up to 24h. This decrease was accompanied by decreases in cAMP, protein kinase A (PKA) activity, and furthermore, significant reduction of pCREB. In conclusion, this study is the first to demonstrate that exposure of arsenite decreases NO production by a reduction of pCREB and PKA activity that may be mediated by cAMP, leading to endothelial dysfunction.