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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 17, Issue 12 - Dec 2007
Volume 17, Issue 11 - Nov 2007
Volume 17, Issue 10 - Oct 2007
Volume 17, Issue 9 - Sep 2007
Volume 17, Issue 8 - Aug 2007
Volume 17, Issue 7 - Jul 2007
Volume 17, Issue 6 - Jun 2007
Volume 17, Issue 5 - May 2007
Volume 17, Issue 4 - Apr 2007
Volume 17, Issue 3 - Mar 2007
Volume 17, Issue 2 - Feb 2007
Volume 17, Issue 1 - Jan 2007
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Bacillus thuringiensis as a Specific, Safe, and Effective Tool for Insect Pest Control
Roh, Jong-Yul ; Choi, Jae-Young ; Li, Ming-Sung ; Jin, Byung-Rae ; Je, Yeon-Ho ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 547~559
Bacillus thuringiensis (Bt) was first described by Berliner  when he isolated a Bacillus species from the Mediterranean flour moth, Anagasta kuehniella, and named it after the province Thuringia in Germany where the infected moth was found. Although this was the first description under the name B. thuringiensis, it was not the first isolation. In 1901, a Japanese biologist, Ishiwata Shigetane, discovered a previously undescribed bacterium as the causative agent of a disease afflicting silkworms. Bt was originally considered a risk for silkworm rearing but it has become the heart of microbial insect control. The earliest commercial production began in France in 1938, under the name Sporeine . A resurgence of interest in Bt has been attributed to Edward Steinhaus , who obtained a culture in 1942 and attracted attention to the potential of Bt through his subsequent studies. In 1956, T. Angus  demonstrated that the crystalline protein inclusions formed in the course of sporulation were responsible for the insecticidal action of Bt. By the early 1980's, Gonzalez et al.  revealed that the genes coding for crystal proteins were localized on transmissible plasmids, using a plasmid curing technique, and Schnepf and Whiteley  first cloned and characterized the genes coding for crystal proteins that had toxicity to larvae of the tobacco hornworm, from plasmid DNA of Bt subsp. kurstaki HD-1. This first cloning was followed quickly by the cloning of many other cry genes and eventually led to the development of Bt transgenic plants. In the 1980s, several scientists successively demonstrated that plants can be genetically engineered, and finally, Bt cotton reached the market in 1996 .
Microbial Community Profiling in cis- and trans-Dichloroethene Enrichment Systems Using Denaturing Gradient Gel Electrophoresis
Olaniran, Ademola O. ; Stafford, William H.L. ; Cowan, Don A. ; Pillay, Dorsamy ; Pillay, Balakrishna ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 560~570
The effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. Accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. Community profiling using PCR targeting the l6S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE) revealed an alteration in the bacterial community profiles with time. Exposure to cis- and trans-dichloroethenes led to the disappearance of certain genospecies that were initially observed in the untreated samples. A cluster analysis of the bacterial DGGE community profiles at various sampling times during the degradation process indicated that the community profile became stable after day 10 of the enrichment. DNA sequencing and phylogenetic analysis of selected DGGE bands revealed that the genera Acinetobacter, Pseudomonas, Bacillus, Comamonas, and Arthrobacter, plus several other important uncultured bacterial phylotypes, dominated the enrichment cultures. Thus, the identified dominant phylotypes may play an important role in the degradation of cis- and trans-dichloroethenes.
Production and Characterization of Monoclonal and Recombinant Antibodies Against Antimicrobial Sulfamethazine
Yang, Zheng-You ; Shim, Won-Bo ; Kim, Min-Gon ; Lee, Kyu-Ho ; Kim, Keun-Sung ; Kim, Kwang-Yup ; Kim, Cheol-Ho ; Ha, Sang-Do ; Chung, Duck-Hwa ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 571~578
A monoclonal antibody (mab) against the antimicrobial sulfamethazine was prepared and characterized by an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA). Sulfamethazine in the range of 0.2 and 45ng/ml could be determined with the mab by IC-ELISA. cDNAs encoding a variable heavy chain and variable light chain of the mab were cloned to produce recombinant antibodies using phage display technology. Following phage rescue and three rounds of panning, a single-chain variable fragment (scFv) antibody with high sulfamethazine-binding affinity was obtained. ELISA analysis revealed that scFv antibody and parent mab showed similar, but not identical, characteristics. The
value by IC-ELISA with scFv antibody was 4.8ng/ml, compared with 1.6ng/ml with the parent mab. Performances of the assays in the presence of milk matrix were compared; the mab-based assay was less affected than the scFv-based assay. Sixty milk samples were analyzed by mab-based IC-ELISA, and four samples were sulfamethazine positive; these results were favorably correlated with those obtained by HPLC.
Expression of Recombinant Human Growth Hormone in a Soluble Form in Escherichia coli by Slowing Down the Protein Synthesis Rate
Koo, Tai-Young ; Park, Tai-Hyun ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 579~585
Formation of inclusion bodies is usually observed when foreign proteins are overexpressed in E. coli. The formation of inclusion bodies might be prevented by lowering the rate of protein synthesis, and appropriate regulation of the protein expression rate may lead to the soluble expression. In this study, human growth hormone (rhGH) was expressed in a soluble form by slowing down the protein synthesis rate, which was controlled in the transcriptional and translational levels. The transcriptional level was controlled by the regulation of the amount of RNA polymerase specific to the promoter in front of the rhGH gene. For lowering the rate of translation, the T7 transcription terminator-deleted vector was used to synthesize the longer mRNA of the target gene because the longer mRNA is expected to reduce the availability of tree ribosomes. In both methods, the percentage of soluble expression increased when the expression rate slowed down, and more than 93% of rhGH expressed was a soluble form in the T7 transcription terminator-deleted expression system.
Inhibition of Seed Germination and Induction of Systemic Disease Resistance by Pseudomonas chlororaphis O6 Requires Phenazine Production Regulated by the Global Regulator, GacS
Kang, Beom-Ryong ; Han, Song-Hee ; Zdor, Rob E. ; Anderson, Anne J. ; Spencer, Matt ; Yang, Kwang-Yeol ; Kim, Yong-Hwan ; Lee, Myung-Chul ; Cho, Baik-Ho ; Kim, Young-Cheol ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 586~593
Seed coating by a phenazine-producing bacterium, Pseudomonas chlororaphis O6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. In wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. Deletion of the gacS gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzI gene and the biosynthetic phzA gene. The inhibition of seed germination and the induction of systemic disease resistance against a bacterial soft-rot pathogen, Erwinia carotovora subsp. carotovora, were impaired in the gacS and phzA mutants of P chlororaphis O6. Culture filtrates of the gacS and phzA mutants of P. chlororaphis O6 did not inhibit seed germination of wheat, whereas that of the wild-type was inhibitory. Our results showed that the production of phenazines by P. chlororaphis O6 was correlated with reduced germination of barley and wheat seeds, and the level of systemic resistance in tobacco against E. carotovora.
Abridged Region from Escherichia coli Periplasmic Stress Sensor DegS Acts as Plasminogen Activator In Vitro
Junpeng, Yan ; Ko, Juho ; Qi, Yipeng ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 594~599
It is well known that the Escherichia coli inner membrane-bound protease DegS is a periplasmic stress sensor for unfolded outer membrane proteins (OMPs). Previous studies have also shown that the outer membrane protease OmpT activates plasminogen in vitro and this may be exploited by bacteria in the course of pathogenesis. However, there has been no research on the plasminogen activation ability of the important periplasmic protein DegS. Accordingly, in this study, the whole-length and truncated degS genes were separately overexpressed in Escherichia coli, the recombinant proteins purified by affinity chromatography, and their plasminogen activator role tested in vitro. The results suggested that the whole-length DegS was able to activate plasminogen on a plasma plate. The truncated form of DegS (residues 80-345), designated
, also acted as a plasminogen activator, as confirmed by different assays. The serine protease property of
was verified based on the complete inhibition of its enzyme activity by PMSF (phenylmethanesulfonyl fluoride). Therefore, the present results indicate that DegS is a plasminogen activator in vitro.
Effect of Ionic Liquid on the Kinetics of Peroxidase Catalysis
Lee, Yoon-Mi ; Kwon, O-Yul ; Yoo, Ik-Keun ; Ryu, Keun-Garp ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 600~603
The effect of a water-miscible ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate
, on the horseradish peroxidase (HRP)-catalyzed oxidation of 2-methoxyphenol (guaiacol) with hydrogen peroxide
was investigated. HRP maintains its high activity in the aqueous mixtures containing various concentrations of the ionic liquid and even in 90% (v/v) ionic liquid. In order to minimize the effect of solution viscosity on the kinetic constants of HRP catalysis, the enzymatic reactions in the subsequent kinetic study were performed in water-ionic liquid mixtures containing 25% (v/v) ionic liquid at maximum. As the concentration of
increased for the oxidation of guaiacol by HRP, the
value increased with a slight decrease in the
value increased from 2.8 mM in 100% (v/v) water to 22.5mM in 25% (v/v) ionic liquid, indicating that ionic liquid significantly weakens the binding affinity of guaiacol to HRP.
Cloning, Expression, and Characterization of a Cold-Adapted Lipase Gene from an Antarctic Deep-Sea Psychrotrophic Bacterium, Psychrobacter sp. 7195
Zhang, Jinwei ; Lin, Shu ; Zeng, Runying ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 604~610
A psychrotrophic strain 7195 showing extracellular lipolytic activity towards tributyrin was isolated from deep-sea sediment of Prydz Bay and identified as a Psychrobacter species. By screening a genomic DNA library of Psychrobacter sp. 7195, an open reading frame of 954 bp coding for a lipase gene, lipA1, was identified, cloned, and sequenced. The deduced LipA1 consisted of 317 amino acids with a molecular mass of 35,210 kDa. It had one consensus motif, G-N-S-M-G (GXSXG), containing the putative active-site serine, which was conserved in other cold-adapted lipolytic enzymes. The recombinant LipA1 was purified by column chromatography with DEAE Sepharose CL-4B, and Sephadex G-75, and preparative polyacrylamide gel electrophoresis, in sequence. The purified enzyme showed highest activity at
, and was unstable at temperatures higher than
, indicating that it was a typical cold-adapted enzyme. The optimal pH for activity was 9.0, and the enzyme was stable between pH 7.0-10.0 after 24h incubation at
. The addition of
enhanced the enzyme activity of LipA1, whereas the
, and EDTA strongly inhibited the activity. The LipA1 was activated by various detergents, such as Triton X-100, Tween 80, Tween 40, Span 60, Span 40, CHAPS, and SDS, and showed better resistance towards them. Substrate specificity analysis showed that there was a preference for trimyristin and p-nitrophenyl myristate
Immunogenicity and Safety of Vi Capsular Polysaccharide Typhoid Vaccine in Healthy Persons in Korea
Lim, Sang-Min ; Jung, Hahn-Sun ; Kim, Min-Ja ; Park, Dae-Won ; Kim, Woo-Joo ; Cheong, Hee-Jin ; Park, Seung-Chul ; Lee, Kwang-Chul ; Shin, Young-Kyoo ; Tan, Hyun-Kwang ; Kim, Sang-Lin ; Sohn, Jang-Wook ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 611~615
The purpose of this study was to evaluate the immunogenicity and safety of Salmonella Typhi Vi capsular polysaccharide vaccine (Vi vaccine) in Korea. The immunogenicity of a single dose of Vi vaccine was evaluated in 157 subjects (75 children and 82 adults) before and at 1, 6, and 12 months after vaccination. Immunogenicity was measured with a passive hemagglutination assay (PHA), quantified as geometric mean titers (GMTs) and seroconversion rates. The safety of the vaccine was investigated by determining adverse reactions occurring within 4h, 3 days, and 1 month after injection. The seroconversion rate for children and adults 1 month after vaccination was 96.92% and 89.02%, respectively. In the case of children, the GMTs of Vi antibodies before vaccination were
at one month after vaccination. For adults, the GMTs before and one month after vaccination were
, respectively. Vi antibodies persisted for as long as 6 and 12 months after vaccination. All adverse reactions in adults and children were minor and did not require treatment. The Vi CPS vaccine was safe and immunogenic in adults and children older than 5 years.
Effects of Inoculum Level and Pressure Pulse on the Inactivation of Clostridium sporogenes Spores by Pressure-Assisted Thermal Processing
Ahn, Ju-Hee ; Balasubramaniam, V.M. ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 616~623
The effects of initial concentration and pulsed pressurization on the inactivation of Clostridium sporogenes spores suspended in deionized water were determined during thermal processing
and pressure-assisted thermal processing
treatments for 40 min and 5min holding times, respectively. Different inoculum levels
of C. sporogenes spores suspended in deionized water were treated at
under 700MPa with single, double, and triple pulses. Thermally treated samples served as control. No statistical significances (p>0.05) were observed among all different inoculum levels during the thermal treatment, whereas the inactivation rates
were decreased with increasing the initial concentrations of C. sporogenes spores during the PATP treatments. Double- and triple-pulsed pressurization reduced more effectively the number of C. sporogenes spores than single-pulse pressurization. The study shows that the spore clumps formed during the PATP may lead to an increase in pressure-thermal resistance, and multiple-pulsed pressurization can be more effective in inactivating bacterial spores. The results provide an interesting insight on the spore inactivation mechanisms with regard to inoculum level and pulsed pressurization.
Purification and Characterization of Two Thermostable Proteases from the Thermophilic Fungus Chaetomium thermophilum
Li, An-Na ; Ding, AI-Yun ; Chen, Jing ; Liu, Shou-An ; Zhang, Ming ; Li, Duo-Chuan ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 624~631
Thermostable protease is very effective to improve the industrial processes in many fields. Two thermostable extracellular proteases from the culture supernatant of the thermophilic fungus Chaetomium thermophilum were purified to homogeneity by tractional ammonium sulfate precipitation, ion-exchange chromatography on DEAE-Sepharose, and Phenyl-Sepharose hydrophobic interaction chromatography. By SDS-PAGE, the molecular mass of the two purified enzymes was estimated to be 33 kDa and 63 kDa, respectively. The two proteases were found to be inhibited by PMSF, but not by iodoacetamide and EDTA. The 33 kDa protease (PRO33) exhibited maximal activity at pH 10.0 and the 63kDa protease (PRO63) at pH5.0. The optimum temperature for the two proteases was
. The PRO33 had a
value of 6.6mM and a
, and PRO63 l7.6mM and
, with casein as substrate. They were thermostable at
. The protease activity of PRO33 and PRO63 remained at 67.2% and 17.31%, respectively, after incubation at
for 1h. The thermal stability of the two enzymes was significantly enhanced by
. The residual activity of PRO33 and PRO63 at
after 60min was approximately 88.59% and 39.2%, respectively, when kept in the buffer containing
. These properties make them applicable for many biotechnological purposes.
A Cytoplasmic Polyhedrosis Virus Isolated from the Pine Processionary Caterpillar, Thaumetopoea pityocampa
Ince, Ikbal Agah ; Demir, Ismail ; Demirbag, Zihni ; Nalcacioglu, Remziye ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 632~637
A cytoplasmic polyhedrosis virus (CPV) was isolated from the larvae of Thaumetopoea pityocampa and shown to cause an infection of midgut cells. This viral infection revealed several important diagnostic symptoms, including discoloration of the posterior midgut, reduced feeding, and extended development time of the larvae. The virus infection is lethal to Thaumetopoea pityocampa, and with the increasing doses kills the larvae within 4-5 days post infection. Electron microscopy studies showed typical cytoplasmic polyhedral inclusion bodies that are icosahedral, and ranged from 2.4 to
in diameter. Electrophoretic analysis of the RNA genome showed that the virus has a genome composed of 10 equimolar RNA segments with the sizes of 3,907, 3,716, 3,628, 3,249, 2,726, 1,914, 1,815, 1,256, 1,058, and 899 bp, respectively. Based on morphology and nucleic acid analysis, this virus was named Thaumetopoea pityocampa cytoplasmic polyhedrosis virus (TpCPV), and belongs to the genus Cypovirus, family Reoviridae.
Stress-Governed Expression and Purification of Human Type II Hexokinase in Escherichia coli
Jeong, Eun-Ju ; Park, Kyoung-Sook ; Yi, So-Yeon ; Kang, Hyo-Jin ; Chung, Sang-J. ; Lee, Chang-Soo ; Chung, Jin-Woong ; Seol, Dai-Wu ; Chung, Bong-Hyun ; Kim, Moon-Il ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 638~643
The full encoding sequence for human type II hexokinase (HXK II) was cloned into the E. coli expression vector pET 21b and expressed as a C-terminally hexahistidine-tagged protein in the BL2l (DE3) strain. The IPTG-induced HXK II approximately accounted for 17% of the total E. coli proteins, and 81% of HXK
existed in inclusion bodies. To improve the production of soluble recombinant HXK II protein, in the functionally active form, we used low temperature, and the osmotic stress expression method. When expressed at
, about 83% of HXK
existed in the soluble fraction, which amounted to a 4.1-fold yield over that expressed at
. The soluble form of HXK
was also highly produced in the presence of 1M sorbitol under the standard condition
, which indicated that temperature downshift and low water potentials were required to improve the yield of active recombinant HXK II protein. The expressed protein was purified by metal chelate affinity chromatography performed in an IDA Excellose column charged with
ions, resulting in about 40mg recombinant HXK II protein obtained with purity over 89% from 51 of E. coli culture. The identity of HXK
was confirmed by Western blotting analysis. Taken together, using the stress-governed expression described in this study, human active HXK II can be purified in sufficient amounts for biochemical and biomedical studies.
A Response Surface Model Based on Absorbance Data for the Growth Rates of Salmonella enterica Serovar Typhimurium as a Function of Temperature, NaCl, and pH
Park, Shin-Young ; Seo, Kyo-Young ; Ha, Sang-Do ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 644~649
Response surface model was developed for predicting the growth rates of Salmonella enterica sv. Typhimurium in tryptic soy broth (TSB) medium as a function of combined effects of temperature, pH, and NaCl. The TSB containing six different concentrations of NaCl (0, 2, 4, 6, 8, and 10%) was adjusted to an initial of six different pH levels (pH 4, 5, 6, 7, 8, 9, and 10) and incubated at 10 or
. In all experimental variables, the primary growth curves were well
fitted to a Gompertz equation to obtain growth rates. The secondary response surface model for natural logarithm transformations of growth rates as a function of combined effects of temperature, pH, and NaCl was obtained by SAS's general linear analysis. The predicted growth rates of the S. Typhimurium were generally decreased by basic (9, 10) or acidic (5, 6) pH levels or increase of NaCl concentrations (0-8%). Response surface model was identified as an appropriate secondary model for growth rates on the basis of coefficient determination
, mean square error (MSE=0.022), bias factor
, and accuracy factor
. Therefore, the developed secondary model proved reliable predictions of the combined effect of temperature, NaCl, and pH on growth rates for S. Typhimurium in TSB medium.
Optimization of Lipase Pretreatment Prior to Lipase Immobilization to Prevent Loss of Activity
Lee, Dong-Hwan ; Kim, Jung-Mo ; Shin, Hyun-Yong ; Kim, Seung-Woo ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 650~654
In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be
, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.
Effect of Dietary Inclusion of Lactobacillus acidophilus ATCC 43121 on Cholesterol Metabolism in Rats
Park, Yoo-Heon ; Kim, Jong-Gun ; Shin, Yong-Won ; Kim, Sae-Hun ; Whang, Kwang-Youn ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 655~662
This study examined the effects of Lactobacillus acidophilus ATCC 43121 (LAB) on cholesterol metabolism in hypercholesterolemia-induced rats. Four treatment groups of rats (n=9) were fed experimental diets: normal diet, normal
, hypercholesterol diet (0.5% cholesterol, w/w), and hypercholesterol diet+LAB. Body weight, feed intake, and feed efficiency did not differ among the four groups. Supplementation with LAB reduced total serum cholesterol (25%) and VLDL+IDL+LDL cholesterol (42%) in hypercholesterol diet groups, although hepatic tissue cholesterol and lipid contents were not changed. In the normal diet group, cholesterol synthesis (HMG-CoA reductase expression), absorption (LDL receptor expression), and excretion via bile acids (cholesterol
expression) were increased by supplementation with LAB, and increased cholesterol absorption and decreased excretion were found in the hypercholesterol diet group. Total fecal acid sterols excretion was increased by supplementation with LAB. With proportional changes in both normal and hypercholesterol diet groups, primary bile acids (cholic and chenodeoxycholic acids) were reduced, and secondary bile acids (deoxycholic and lithocholic acids) were increased. Fecal neutral sterol excretion was not changed by LAB. In this experiment, the increase in insoluble bile acid (lithocholic acid) reduced blood cholesterol level in rats fed hypercholesterol diets supplemented with LAB. Thus, in the rat, L. acidophilus ATCC 43121 is more likely to affect deconjugation and dehydroxylation during cholesterol metabolism than the assimilation of cholesterol into cell membranes.
Morphological Changes Induced in Listeria monocytogenes V7 by a Bacteriocin Produced by Pediococcus acidilactici
Heo, Seok ; Lee, Si-Kyung ; Lee, Chi-Ho ; Min, Sang-Gi ; Park, Jong-Seok ; Kim, Hee-Yun ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 663~667
Pediococcus acidilactici produces bacteriocin, which kills Listeria monocytogenes. The bactericidal mode of action of the bacteriocin against L. monocytogenes V7 was investigated by transmission electron microscopy. The bacteriocin was purified partially from the cell-free extract using Micro-Cel and cation-exchange chromatography, and the specific activity was increased 1,791 fold. The bacteriocin (6,400 AU/ml) was inoculated with L. monocytogenes V7 and incubated for 0.5h, 1h, 3h, and 6h. The bacteriocin was found to destroy most of the cell wall and released most of the inclusions in the cells after 6 h of incubation. These results suggest that the bactericidal effect of the bacteriocin was due to bacterial lysis.
Metagenomic Analysis of BTEX-Contaminated Forest Soil Microcosm
Ji, Sang-Chun ; Kim, Doc-Kyu ; Yoon, Jung-Hoon ; Lee, Choong-Hwan ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 668~672
A microcosmal experiment using a metagenomic technique was designed to assess the effect of BTEX (benzene, toluene, ethylbenzene, and xylenes) on an indigenous bacterial community in a Daejeon forest soil. A compositional shift of bacterial groups in an artificial BTEX-contaminated soil was examined by the 16S rDNA PCR-DGGE method. Phylogenetic analysis of 16S rDNAs in the dominant DGGE bands showed that the number of Actinobacteria and Bacillus populations increased. To confirm these observations, we performed PCR to amplify the 23S rDNA and 16S rDNA against the sample metagenome using Actinobacteria-targeting and Bacilli-specific primer sets, respectively. The result further confirmed that a bacterial community containing Actinobacteria and Bacillus was affected by BTEX.
Detection of Methicillin Resistance in Staphylococcus aureus Isolates Using Two-Step Triplex PCR and Conventional Methods
Cho, Joon-Il ; Jung, Hye-Jin ; Kim, Young-Joon ; Park, Sung-Hee ; Ha, Sang-Do ; Kim, Keun-Sung ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 673~676
A two-step triplex PCR assay targeting the mecA, femA, and nuc genes was developed for the detection of methicillin resistance genes harbored by some Staphylococcus aureus isolates and for the simultaneous identification of such isolates at the species level. The triplex PCR revealed the presence of the femA and nuc genes in all the S. aureus isolates examined (n=105). Forty-four clinical isolates were mecA positive and no foodborne isolates were mecA positive. The PCR results had a 98 or 99% correlation with the results of PBP2a latex agglutination tests or oxacillin susceptibility tests, respectively.
Bacterial Surface Display of
on Bacillus subtilis Spores
Kim, Jung-Hyung ; Roh, Chang-Hyun ; Lee, Chang-Won ; Kyung, Do-Hyun ; Choi, Soo-Keun ; Jung, Heung-Chae ; Pan, Jae-Gu ; Kim, Byung-Gee ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 677~680
To analyze a cotG-based Bacillus subtilis spore display system directly,
was expressed on the surface of Bacillus subtilis spores. When
was fused to the C-terminal of the cotG structural gene and expressed, the existence of a
fusion protein on the B. subtilis spore was confirmed by flow cytometry confocal microscopic analysis. When the cotG anchoring motif was deleted, no fluorescence emission was observed under flow cytometry and confocal microscopic analysis from the purified spore, confirming the essential role of CotG as an anchoring motif. This
displaying spore might be used for another signaling application triggered by intracellular or extracellular stimuli.
Quantitative Analysis of Phosphinothricin-N-acetyltransferase in Genetically Modified Herbicide Tolerant Pepper by an Enzyme-Linked Immunosorbent Assay
Shim, Youn-Young ; Shin, Weon-Sun ; Moon, Gi-Seong ; Kim, Kyung-Hwan ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 681~684
An immunoassay method was developed to quantitatively detect phosphinothricin-N-acetyltransferase (PAT) encoded by the Bialaphos resistance (bar) gene in genetically modified (GM) pepper. The histidine-tagged PAT was overexpressed in Escherichia coli M15 (pQE3l-bar) and efficiently purified by
affinity chromatography. A developed sandwich enzyme-linked immunosorbent assay (S-ELISA) method (detection limit:
) was 100-fold more sensitive than a competitive indirect ELISA (CI-ELISA) method or Western blot analysis in detecting the recombinant PAT. In real sample tests, PAT in genetically modified herbicide-tolerant (GMHT) peppers was successfully quantified [
of sample (n=6)] by the S-ELISA method. The S-ELISA method developed here could be applied to other GMHT crops and vegetables producing PAT.
Cloning and Expression of Glucose-1-Phosphate Thymidylyltransferase Gene (schS6) from Streptomyces sp. SCC-2136
Han, Ji-Man ; Kim, Su-Min ; Lee, Hyo-Jung ; Yoo, Jin-Cheol ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 685~690
The deoxysugar biosynthetic gene cluster of Sch 47554/Sch 47555 was cloned from Streptomyces sp. SCC-2136. One of the ORFs, schS6, appeared to encode glucose-1-phosphate thymidylyltransferase, which converts dTTP and glucose-1-phosphate to TDP-D-glucose and pyrophosphate. The dTDP-D-glucose is a key metabolite in prokaryotics as a precursor for a large number of modified deoxysugars, and these deoxysugars are a maj or part of various antibiotics, ranging from glycosides to macrolides. SchS6 was expressed in E. coli vector pSCHS6 and the expressed protein was purified to apparent homogeneity by ammonium sulfate precipitation and Ni-NTA affinity column chromatography. The specific activity of the purified enzyme increased 4.7-fold with 17.5% recovery. It migrated as a single band on SDS-PAGE with an apparent molecular mass of 56kDa. The purified protein showed glucose-1-phosphate thymidylyltransferase activity, catalyzing a reversible bimolecular group transfer reaction. In the forward reaction, the highest activity was obtained with combination of dTTP and
, and only 12% of that activity was obtained with the substrates
. In the opposite direction, the purified protein was highly specific for dTDP-D-glucose and pyrophosphate.
Production of Weak Acid by Anaerobic Fermentation of Soil and Antifungal Effect
Kim, Hong-Lim ; Jung, Bong-Nam ; Sohn, Bo-Kyoon ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 691~694
Acetic acid and butyric acid were produced by the anaerobic fermentation of soil mixed with wheat or rice bran. The concentration of acetic acid produced in the wheat and rice bran-treated soil was 31.2mM and 8mM, respectively, whereas the concentration of butyric acid in the wheat and rice bran-treated soil was 25.0mM and 8mM, respectively. The minimal fungicidal concentration (MFC) for all the fungal strains was 40-60mM acetic acid, 20-40mM butyric acid, and 40-60mM mixture of acetic acid: butyric acid (1:1, v/v). Consequently, the efficacy of mixing wheat-bran with soil to control soil diseases was demonstrated.
Characterization of Cyclofructans from Inulin by Saccharomyces cerevisiae Strain Displaying Cell-Surface Cycloinulooligosaccharide Fructanotransferase
Kim, Hyun-Jin ; Lee, Jae-Hyung ; Kim, Hyun-Chul ; Lee, Jin-Woo ; Kim, Yeon-Hee ; Nam, Soo-Wan ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 695~700
The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans (GenBank access code AF222787) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein Aga1p. The surface display of CFTase was confirmed by immunofluorescence microscopy and enzymatic assay. The optimized reaction conditions of surface-displayed CFTase were as follows; pH, 8.0; temperature,
; enzyme amount, 30 milliunit; substrate concentration, 5%; inulin source, Jerusalem artichoke. As a result of the reaction with inulin, cycloinulohexaose was produced as a major product along with cycloinuloheptaose and cycloinulooctaose as minor products.
Comparison of Full Genome Sequences Between Two Hepatitis B Virus Strains With or Without preC Mutation (A1896) from a Single Korean Hepatocellular Carcinoma Patient
Kim, Hong ; Jee, Young-Mee ; Mun, Ho-Suk ; Song, Byung-Cheol ; Park, Joo-Hee ; Hyun, Jin-Won ; Hwang, Eung-Soo ; Cha, Chang-Yong ; Kook, Yoon-Hoh ; Kim, Bum-Joon ;
Journal of Microbiology and Biotechnology, volume 17, issue 4, 2007, Pages 701~704
This report describes the full-length sequences of 2HBV clones from a hepatocellular carcinoma (HCC) patient, one with preC mutation (1896A) and the other without preC mutation. The high level of discrepancy in mutation frequency between these 2 strains was observed in the Core (C) region among 4 ORFs. These data support previous results that Korean HBV strains, belonging to genotype C2, are prone to mutations. It is possible that the mutations (BCP and preC mutations) associated with the HBeAg defective production might contribute to the diversity of mutations related to HBV persistence, playing an important role in hepatocarcinogenesis in this patient.