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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Korean Journal of Microbiology
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Journal DOI :
The Microbiological Society of Korea
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Volume & Issues
Volume 45, Issue 4 - Dec 2009
Volume 45, Issue 3 - Sep 2009
Volume 45, Issue 2 - Jun 2009
Volume 45, Issue 1 - Mar 2009
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Efficacy of Genetic Adjuvant (Plasmid-Expressed Chicken Interleukin-6) and Chemical Adjuvant (Levamisole) on the Protective Immunity of Genetic Vaccine against Infectious Bursal Disease Virus
Park, Jeong-Ho ; Sung, Haan-Woo ; Yoon, Byung-Il ; Pak, Son-Il ; Kwon, Hyuk-Moo ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 91~98
Infectious bursal disease (IBD) caused by the infectious bursal disease virus (IBDV) has an important economic impact on the poultry industry worldwide. This study examined the adjuvant effects of a plasmid encoding chicken interleukin-6 (pcDNA-ChIL-6) and levamisole (LMS) on in ovo prime-boost vaccination using a genetic vaccine (pcDNA-VP243) to prime in chicken followed by a killed-vaccine boost. A pcDNA-VP243 was injected into the amniotic sac alone or in combination with a pcDNA-ChIL-6 or LMS at embryonation day 18, followed by an intramuscular injection of killed IBD vaccine at 1 week of age. The chicken were orally challenged with very virulent IBDV (vvIBDV) strain at 3 weeks of age and observed for 10 days. No mortality was observed in the groups that received the pcDNA-VP243 alone and pcDNA-VP243 plus pcDNA-ChIL-6 or LMS compared to 100% mortality in unvaccinated challenge control group. However, as determined by bursal damage (the presence of IBDV RNA, B/B ratio, and lesion score), a pcDNA-VP243 alone group was superior to pcDNA-VP243 plus pcDNA-ChIL-6 or LMS groups in the protection against post-challenge. These findings suggest that in ovo priming with genetic vaccine and boosting with killed vaccine is an effective strategy for protecting chicken against vvIBDV and the addition of pcDNA-ChIL-6 or LMS did not enhance protective immunity.
Antimicrobial Resistance and Multidrug Resistance Patterns of Salmonella enterica serovar Enteritidis Isolated from Diarrhea Patients, Incheon
Hwang, Kyoung-Wha ; Oh, Bo-Young ; Kim, Jung-Hee ; Kim, Myeong-Hee ; JeGal, Seung ; Lee, Eun-Ju ; Lee, Eun-Jung ; Cho, Nam-Kyu ; Go, Jong-Myoung ; Kim, Yong-Hee ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 99~104
This study describes the antimicrobial susceptibility and multidrug resistance patterns in 115 isolates of Salmonella enterica serovar Enteritidis from diarrhea patients in Incheon from Jan. 2004 to Dec. 2008. Overall, the highest rate of resistance was found to the following antimicrobial agents: nalidixic acid 54.8%, ampicillin 40.0%, ticarcillin 38.3%, chloramphenicol 20.9%, and tetracycline 17.4%. 91% (104 isolates) were resistant to one or more antimicrobial agents tested. Among the described antimicrobial resistant patterns, the predominant patterns were only nalidixic acid (44.3%), ampicillin-chloramphenicol-ticarcillin (11.3%,) and ampicillin-ticarcillin (10.4%). Overall, the resistant rate to one drug was 51.9%, two drugs 18.2%, three drugs 14.5%, four drugs 5.8%, and five or more drugs 9.7%.
Molecular Characterization of a Korean Isolate of Human Norovirus, the Hu/NLV/Gunpo/2006/KO Strain
Jeong, Ah-Yong ; Yun, Sang-Im ; Jee, Young-Mee ; Kang, Yoon-Sung ; Lee, Young-Min ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 105~111
Norovirus (NV) with a variety of genotypes, a member of the family Caliciviridae, causes acute nonbacterial gastroenteritis in humans. We determined the nucleotide sequence of three open reading frames (ORFs) of a NV Korean strain and characterized the genetic relationship with others. The Korean strain designated Hu/NLV/Gunpo/2006/KO was isolated from the stool specimen of a 2-year-old female suffering from gastroenteritis. By performing reverse transcription and PCR amplification, three overlapping cDNAs were synthesized and used for direct sequencing. We found that like other NVs, this strain contains three ORFs: ORF1, 5,100 bp; ORF2, 1,647 bp; ORF3, 765 bp. Of 35 NVs, ORF1 had a level of genetic diversity lower than ORF2 and ORF3, of which the C-termini of the ORF2 and ORF3 showed a relatively high degree of genetic diversity. Phylogenetic analyses indicated that the Korean strain belonged to genogroup II, with Saitama U1, Gifu'96, Mc37, and Vietnam 026 being formed a single genetic cluster. The nucleotide sequence information of three ORFs of a NV Korean isolate will be useful not only for the development of a diagnostic tool and understanding of genetic relationship, but also provide important basic information for the functional analysis of their gene products.
Characterization and Composition of Ammonia-Oxidizing Bacterial Community in Full- Scale Wastewater Treatment Bioreactors
Park, Hee-Deung ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 112~118
Ammonia-oxidizing bacteria (AOB) are chemolithoautotrophs that play a key role in nitrogen removal from advanced wastewater treatment processes. Various AOB species inhabit and their community compositions vary over time in the wastewater treatment bioreactors. In this study, a hypothesis that operational and environmental conditions affect both the community compositions and the diversity of AOB in the bioreactors was proposed. To verify the hypothesis, the clone libraries based on ammonia monooxygenase subunit A were constructed using activated sludge samples from aerobic bioreactors at the Pohang, the Palo Alto, the Nine Springs, and the Marshall wastewater treatment plants (WWTPs). In those bioreactors, AOB within the Nitrosomonas europaea, N. oligotropha, N.-like, and Nitrosospira lineages were commonly found, while AOB within the N. communis, N. marina, and N. cryotolerans lineages were rarely detected in the samples. The AOB community structures were different in the bioreactors: AOB within the N. oligotropha lineage were the major microorganisms in the Pohang, the Palo Alto, and the Marshall WWTPs, while AOB within the N. europaea lineage were dominant in the Nine Springs WWTP. The correlations between the AOB community compositions of the wastewater treatment bioreactors and their operational (HRT, SRT, and MLSS) and environmental conditions (temperature, pH, COD,
) were evaluated using a multivariate statistical analysis called the Redundancy Analysis (RDA). As a result, COD and
concentrations in the bioreactors were the statistically significant variables influencing the AOB community structures in the wastewater treatment bioreactors.
Distribution of Bacterial Decomposers in Lake Khuvsgul, Mongolia
Jung, You-Jung ; Jung, Da-Woon ; Kim, Ju-Young ; Zo, Young-Gun ; Yim, Joung-Han ; Lee, Hong-Kum ; Ahn, Tae-Seok ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 119~125
To understand the ecological function of heterotrophic bacterial community in water column of large freshwater lakes in the permafrost zone, we investigated the structure and function of bacterial community in Lake Khuvsgul, Mongolia. Species composition of overall bacterial community was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments, and bacteria that can be cultured at 10oC were isolated and characterized. Based on the depth profile of environmental parameters, thermocline and chemocline were recognized at the 5~10 m zone of the water column. The stratified DGGE profile indicated that the discontinuity of water properties might influence the structure of bacterial community: band profiles in the 0~5 m zone were diverse with large change by depth, but the profile was relatively stable at the
10 m zone, with predominance of the band identified as Acidovorax facilis. Bacterial cultures were screened for protease, cellulase, amylase and lipase activity, and 23 isolates were selected for high activity of the hydrolytic enzymes. The isolates were identified based on their 16S rRNA gene sequences. In the surface water (zero meter depth), Acidovorax defluvii and Sphingobacterium faecium with high cellulase activity were present. Flavobacterium succinicans, Mycoplana bullata and A. facilis were stably predominant isolates at 2 m, 5 m, and
10 m depths, respectively. F. succinicans isolates showed high protease activity while M. bullata isolates showed moderate levels of protease and celluase activity. A. facilis isolates showed either cellulase or lipase activity, exclusively to each other. According to the profile of growth rates of the isolates in the temperature range of
, the surface-zone (0~5 m) isolates were facultative psychrophiles while isolates from
10 m depth were typical mesophiles. This stratification is believed to be due to stratified availability of organic materials to the bacterial decomposers. In the water column below the chemoline, the environment is extremely oligotrophic so that the trait of rapid growth in low temperature might not be demanded by deep-lake decomposers. The stratified distribution of community composition and decomposer activity in Lake Khuvsgul implies that ecological functions of bacterial community in lakes of cold region are sharply divided by water column stratification.
Molecular Epidemiological Relationship of the Pathogenicity of Legionella spp. Isolated from Water Systems in Seoul
Kim, Jin-Ah ; Jung, Ji-Hun ; Kim, Soo-Jin ; Jin, Young-Hee ; Oh, Young-Hee ; Han, Gi-Young ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 126~132
Legionella spp. is the causative agent of Legionellosis, which induces a potentially fatal form of pneumonia. With a concentrated performance during the summer of 2008, we secured 73 isolates from the water systems of 25 wards in Seoul. We analysed serotypes, pathogenic genes (Dot/Icm), and patterns of pulsed-field gel electrophoresis (PFGE) in an attempt to confirm relationships among them. Different from the previous year's pattern (2007), among the isolates, 69 were Legionella pneumophila and 4 were Legionella spp. The serotype distribution of Legionella pneumophila was sg1 43, sg6 9, sg5 8, sg3 8, and sg2 1. The serotype for the 4 Legionella spp. was Legionella nautarum. Most of the Legionella pneumophila had several pathogenic genes. On the other hand, the 4 Legionella spp. were defective in pathogenicity in genomic terms. The PFGE patterns of the serotypes showed a tendency for diversity of Legionella pneumophila and a close correlation with genetic pathogenicity.
Dynamics of Total Phosphorus and Attached Bacteria in a Porous Medium Concentrating Nutrients from Low-Nutrient Water
Kim, Ju-Young ; Nam, Jong-Hyun ; Jung, Da-Woon ; Cho, Ahn-Na ; Choi, Seung-Ik ; Ahn, Tae-Seok ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 133~139
A nutrient-concentrating system was operated to retrieve total phosphorus efficiently from a non-point pollution source. Attached bacteria were expected to play an important role in the system. Phosphorous was concentrated by formation of bacterial biofilms on rubberized coconut fiber media of the system. While concentration of total phosphorus (TP) ranged merely 0.12~0.35 mg/L in the stream water, TP levels in pore water and the media were 0.45~0.86 mg/L and 40.91~242.71 mg/kg, respectively. Total bacterial number (TBN) ranged
cells/ml in stream water,
cells/ml in pore water and
cells/g in media. There was a close correlation between TP and TBN. Based on band profiles in DGGE analyses, bacterial communities in the media were different from that in the stream water. Clostridium spp. were abundant in the stream water while Aquabacterium spp. were dominant species in early stages of biofilm formation in the media. The genera predominant in matured biofilms of the media were Clostridium and Enterococcus.
Analysis of Microbial Community During the Anaerobic Dechlorination of Tetrachloroethylene (PCE) in Stream of Gimpo and Inchon Areas
Kim, Byung-Hyuk ; Baek, Kyung-Hwa ; Cho, Dea-Hyun ; Sung, Youl-Boong ; Ahn, Chi-Yong ; Oh, Hee-Mock ; Koh, Sung-Cheol ; Kim, Hee-Sik ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 140~147
In this study, anaerobic enrichment cultivation was performed with the sediments from the Gimpo and Inchon areas. Lactate as an electron donor and PCE as an electron acceptor was injected into the serum bottle with an anaerobic medium. After the incubation of 8 weeks, the reductive dechlorination of PCE was observed in 7 sites among 16 sites (43%). Three enrichment cultures showed completely dechlorination of PCE to ethene, while four enrichment culture showed transformation of PCE to cis-DCE. The bacterial community structure was analyzed by PCR-DGGE. Dechlorinating bacteria were detected by species-specific primers. The dominant species in seven anaerobic enrichments were found to belong to the genus of Dehalococcoides sp. and Geobacter sp., and Dehalobacter sp.
Bacterial Community Dynamics during Composting of Food Wastes
Shin, Ji-Hye ; Lee, Jin-Woo ; Nam, Ji-Hyun ; Park, Se-Yong ; Lee, Dong-Hun ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 148~154
Composting is a biological process converting solid organic waste into valuable materials such as fertilizer. The change of bacterial populations in a composting reactor of food waste was investigated for 2 months. Based on shifts in temperature profile, the composting process could be divided into the first phase (
), the second phase (
), and the third phase (
). The number of total bacteria was
cell/g in the first, second, and third stages, respectively. The proportions of thermophiles increased from 33% to 89% in the second stage. T-RFLP analysis and nucleotide sequencing of 16S rRNA gene demonstrated that the change of bacterial community structure was coupled with shifts in composting stages. The structure of bacterial community in the ultra-thermophilic second stage reflected that of seeding starter. The major decomposers driving the ultra-thermophilic composting were identified as phylotypes related to Bacillus and Pseudomonas.
Comparative Analysis of the Community of Culturable Bacteria Associated with Sponges, Spirastrella abata and Spirastrella panis by 16S rDNA-RFLP
Cho, Hyun-Hee ; Park, Jin-Sook ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 155~162
A cultivation-based approach was employed to compare the culturable bacterial diversity associated with two phylogenetically closely related marine sponges, Spirastrella abata and Spirastrella panis, which have geologically overlapping distribution patterns. The bacteria associated with sponge were cultivated using MA medium supplemented with 3% sponge extracts. Community structures of the culturable bacteria of the two sponge species were analyzed with PCR-RFLP (restriction fragment length polymorphism) based on 16S rDNA sequences. The RFLP fingerprinting of 16S rDNA digested with HaeIII and MspI, revealed 24 independent RFLP types, in which 1-5 representative strains from each type were partially sequenced. The sequence analysis showed >98.4% similarity to known bacterial species in public databases. Overall, the microbial populations of two sponges investigated were found to be the members of the classes; Alphaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria. The Alphaproteobacteria were predominant in the bacterial communities of the two sponges. Gammaproteobacteria represented 38.5% of bacterial community in S. abata. Whereas only 1.6% of this class was present in S. panis. Bacillus species were dominat in S. panis. Bacillus species were found to be 44.3% of bacterial species in S. panis, while they were only 9.7% in S. abata. It is interesting to note that Planococcus maritimus (8.1%, phylum Firmicutes) and Psychrobacter nivimaris (28.9%, phylum Gammaproteobacteria) were found only in S. abata. This result revealed that profiles of bacterial communities from the sponges with a close phylogenetic relationship were highly species-specific.
The Types of Extended-Spectrum
-Lactamase (ESBL) Produced by Enteric Bacteria, Klebsiella pneumoniae and Escherichia coli Isolated from Sewage of Wastewater Treatment Plant at Minragdong in Busan, Korea
Lee, Hun-Ku ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 163~169
This study was performed to investigate the type of extended-spectrum
-lactamases (ESBL) produced by bacteria isolated from the sewage of wastewater treatment plant at Minragdong, Suyong-gu in Busan. The facility is located at sushi restaurants and guides its drain water to the wastewater treatment plant at Yonghodong, Nam-gu in Busan. Samples were collected on January, 2009. A total of 19 strains were selected as potential ESBL positive strains through a double disk synergy test. On the basis of the results from biochemical tests including indole, methyl-red, Voges-Proskauer, Simmon's citrate, decarboxylase-dihydrolase and sugar-fermentation tests, the 19 strains were identified with 16 strains of Escherichia coli and 3 strains of Klebsiella pneumoniae. Out of 19 strains, 4 transconjugants against Escherichia coli J53, which is sodium azide resistant recipient strain, were obtained. The plasmids isolated from transconjugants were used for PCR analysis. The type of each extended-spectrum
-lactamase (ESBL) produced by the strains was determined on the basis of isoelectric focusing analysis and DNA sequencing. The results indicated that the types of ESBL from Klebsiella pneumoniae were SHV-12 (3 strains), and Escherichia coli was SHV-12/TEM-1 (1 strain), respectively.
Community Structure of Bacteria Associated with Two Marine Sponges from Jeju Island Based on 16S rDNA-DGGE Profiles
Park, Jin-Sook ; Sim, Chung-Ja ; An, Kwang-Deuk ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 170~176
Culture-independent 16S rDNA-DGGE profiling and phylogenetic analysis were used to examine the predominant bacterial communities associated with the two sponges, Dictyonella sp. and Spirastrella abata from Jeju island. The culture-independent approach involved extraction of total bacterial DNA, PCR amplification of the 16S ribosomal DNA using primer pair 341f-GC and 518r, and separation of the amplicons on a denaturing gradient gel. Denaturing gradient gel electrophoresis banding patterns indicated 8 and 7 bands from the two sponge species, Dictyonella sp. and Spirastrella abata, respectively. There were not common major bands in two different sponges. Comparative sequence analysis of variable DGGE bands revealed from 93% to 98% similarity to the known published sequences. The dominant bacterial group of Dictyonella sp. belonged to uncultured Gammaproteobacteria, while, that of Spirastrella abata belonged to uncultured Alphaproeobacteria and Firmicutes. DGGE analysis indicated predominant communities of the sponge-associated bacteria differ in the two sponges from the same geographical location. This result revealed that bacterial community profiles of the sponges were host species-specific.
Probiotic Property of Lactobacillus pentosus Miny-148 Isolated from Human Feces
Jung, Min-Young ; Park, Yong-Ha ; Kim, Hyun-Soo ; Poo, Ha-Ryoung ; Chang, Young-Hyo ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 177~184
Three hundred lactic acid bacteria isolated from human feces were studied their probiotic characters to develop potential probiotics. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, thermal stability, antimicrobial, anticancer cell, and antiviral activity. Strain Miny-148 was selected as a potential probiotic bacterium which showed resistance to low pH, bile salts and thermal stability. On the basis of fatty acid profiles and 16S rDNA sequences analysis, the strain was identified as Lactobacillus pentosus (similarity 99.9%). The strain, L. pentosus Miny-148, showed broad antimicrobial spectrum against E. coli O157:H7, Shigella flexneri, Bacillus anthracis, Staphylococcus aureus, E. coli, Vibrio cholerae, V. vulnificus, Salmonella typhimurium, and Methicillin-resistant S. aureus (MRSA). Cell-free culture supernatant of the strain also inhibited against the growth of HT-29 colon cancer cell and transmissible gastroenterits virus.
Characterization and Production of Antibiotic by Bacillus subtilis 028-1, a Chungkookjang Fermenting Strain
Ahn, Kyung-Joon ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 185~192
Chungkookjang fermenting Bacillus subtilis 028-1 strain suppressed the growth of Staphylococcus sp. LS2, Saccharomyces cerevisiae, and Candida albicans. B. subtilis 028-1 strain produced antibiotic effectively in the medium of 2% soybean meal and 1% maltose as a disaccharide, when the shaking was continued 15~18 h and the pH of culture medium was maintained under 6.5. The antibiotic activity was optimized when the initial pH of the culture medium of test strain was adjusted with weak alkali, was remained after 20 min of boiling and for more than 1 month in room temperature, and was weakened slowly by the digestion of chymotrypsin and papain. The molecular weight of the antibiotic was identified between 500 and 1,000 dalton by dialysis, and antibiotic substance was considered as not surfactin but a member of iturin family because of the absence of fibrinolytic activity.
Isolation and Identification of Halotolerant Bacillus sp. SJ-10 and Characterization of Its Extracellular Protease
Kim, Eun-Young ; Kim, Dong-Gyun ; Kim, Yu-Ri ; Choi, Sun-Young ; Kong, In-Soo ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 193~199
A bacterium producing the halotolerant extracellular protease was isolated from squid jeotgal, and was identified as Bacillus sp. SJ-10 based on morphological, physiological and biochemical characteristics, as well as phylogenetic analysis using 16S rRNA gene sequence. The strain grew at
, pH 5~8, and 0%~14% NaCl and optimal growth conditions were
, pH 7, and 5% NaCl. The major cellular fatty acids were anteiso-
DNA G+C content was 50.58 mol% and menaquinone consisted of MK-7 Phylogenic analysis based on the 16S rRNA gene sequence indicated that SJ-10T belongs to the genus Bacillus. About 40 kDa of the salt-tolerant protease was purified by 40% ammonium sulfate saturation and Mono Q column chromatography. The optimal activity of the protease was pH 8 and stable at pH 5~10. The optimum temperature and NaCl concentration were
Characterization of Erythritol 4-Phosphate Dehydrogenase from Penicillium sp. KJ81
Yun, Na-Rae ; Park, Sang-Hee ; Lim, Jai-Yun ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 200~207
In this study, the characterization of purified erythritol 4-phosphate dehydrogenase, key enzyme of erythritol biosynthesis, produced by Penicillium sp. KJ81 was investigated. Optimum production conditions of erythritol 4-phosphate dehydrogenase was 1 vvm areration, 200 rpm agitation, at
for 8 days in the medium containing 30% sucrose, 0.5% yeast extract, 0.5%
, and 0.05%
. Erythritol 4-phosphate dehydrogenase was purified through ultrafiltration and preparative gel electrophoresis from cell extract of Penicillium sp. KJ81. This enzyme was especially active on erythrose 4-phosphate with 1.07 mM of Km value. It gave a single band on native polyacrylamide gel electrophoresis and an isoelectric point of 4.6. The enzyme had an optimal activity at pH 7.0 and
. It was stable between pH 4.0 and 9.0, and also below
. The enzyme activity was completely inhibited by 1mM
and 1 mM
, but was not significantly affected by other cations tested. This enzyme was inactivated by treatment of tyrosine specific reagent, iodine and tryptophan specific reagent, N-bromosuccinimide. The substrate of the enzyme, erythrose 4-phosphate showed protective effect on the inactivation of the enzyme by both reagents. These results suggest that tryptophan and tyrosine residues are probably located at or near active site of the enzyme.
Reevaluation of Enumeration of Bacillus cereus Grown on Mannitol-Egg York-Polymyxin B Agar
Yun, Suk-Hyun ; Kim, Yong-Sang ; Jeong, Do-Yeon ; Hahn, Kum-Su ; Uhm, Tai-Boong ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 208~214
To avoid ambiguity in counting the number of colony, about 1,500 of colonies grown on B. cereus selective agar plates were grouped into 12 types by morphological difference and then identified by biochemical and 16S rDNA nucleotide sequence. Among them, seven colony types with 11 to 15 mm diameters of halo were identified as B. cereus or B. cereus subsp. cytotoxis. Five mm sized colonies with no halo, which have not been considered as B. cereus according to the manufacturer's manual, were identified as B. cereus. A colony type with double halos of only 6 mm in diameter was also B. cereus. Other three types were proven to be Enterococcus sp., Brevibacillus sp., and B. subtilis, respectively. PCR results showed that only 9 types that are identified as B. cereus strains harbor at least one of B. cereus toxin genes.
Establishment of an In Vivo Report System for the Evaluation of Amber Suppression Activity in Escherichia coli
Kim, Kyung-Tae ; Park, Mi-Young ; Park, Jung-Chan ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 215~221
Site-specific incorporation of unnatural amino acids into proteins in vivo can be achieved by co-expression of an orthogonal pair of suppressor tRNA and engineered aminoacyl-tRNA synthetase (ARS) that specifically ligates an unnatural amino acid to the suppressor tRNA. As a step to establish this technique, here we generated an Escherichia coli reporter strain DH10B(Tn:lacZam) by integrating amber mutated lacZ gene into the chromosome of E. coli DH10B strain. In vivo expression of E. coli amber suppressor
produced blue colonies in culture plates containing X-Gal as well as dramatically increased
-galactosidase activity. In addition, expression of an orthogonal pair of Saccharomyces cerevisiae suppressor
and tyrosyl-tRNA synthetase also produced blue colonies as well as moderate increase of
-galactosidase activity. These data demonstrate that our reporter strain will provide an efficient method to assess amber suppression in both qualitative and quantitative manners.
Seasonal Distribution of Bacterial Populations and Escherichia coli O157 at Hanwoo Cattle Feedlots in Gyeongsangbuk-do
Khang, Yong-Ho ; Kang, Moon-Sook ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 222~227
The seasonal variation of bacterial populations in the Korean cattle (Hanwoo) feedlots dispersed in the 20 cities of Gyeongsangbuk-do, Korea, was monitored for two years (2006 and 2007) to provide quantitative criteria for good agricultural management. Outside the feedlots, the average falling bacterial populations of the air were
min (n=63) in a year. Inside the feedlots, the average falling bacterial populations of the air were
min (n=63) in the spring,
min (n=69) in the summer,
min (n=69) in the autumn, and
min (n=70) in the winter. Without using the summer data, the average falling bacterial population of the air was
min, which was not statistically significant (P=0.37). The average bacterial populations in the cattle drinking water of the cattle feedlots were
CFU/ml (n=65) in the spring,
CFU/ml (n=65) in the summer,
CFU/ml (n=64) in the autumn, and
CFU/ml (n=64) in the winter. Without using the summer data, the average bacterial population of the drinking water was
CFU/ml, which was statistically significant (P=0.027). The average frequency of Escherichia coli O157 inside the feedlots was 5% (n=65) in the spring, 72% (n=65) in the summer, 67% (n=66) in the autumn, and 29% (n=66) in the winter on the basis of soil samples of the year 2007. The results indicate that most of the Escherichia coli O157 strains distributed in the summer and autumn was disappeared in the spring through the cold weather of the winter.
Pepper Blight Disease Inhibition Metagenome Clone Screening Using Soil Metagenome Library
Park, Hae-Chul ; Sung, So-Ra ; Kim, Dong-Gwan ; Koo, Bon-Sung ; Jeong, Byeong-Moon ; Kim, Jin-Heung ; Yoon, Moon-Young ;
The Korean Journal of Microbiology, volume 45, issue 2, 2009, Pages 228~231
We have purified Phytophthora capsici alpha and beta tubulin from Escherchia coli BL21(DE3). The recombinant alpha and beta tubulins were assembled into microtubule in vitro with specific conditions. The metagenome library was isolated from soil in the Mt. Yeo-Ki, Suwon, Korea and manufactured with the method mentioned in experiment contents for in vitro screening of microtubule assembly screening. FRET effect was used for microtubule assembly inhibitor screening with metagenome library. We got 2 metagenome clones from in vitro screening, and these 2 hit clones showed P. capsici growth inhibition activity on the growing pepper plants. These results suggest that new development of potent inhibitor for pepper blight disease and new approach to prevention of pepper blight disease.