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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 50, Issue 4 - Dec 2014
Volume 50, Issue 3 - Sep 2014
Volume 50, Issue 2 - Jun 2014
Volume 50, Issue 1 - Mar 2014
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Development of a Quantitative Induction Method for Chondromyces crocatus Fruiting Body Formation
Lee, Chayul ; Shin, Hyejin ; Cho, Kungyun ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 173~178
DOI : 10.7845/kjm.2014.4042
We have developed a method for the preparation of dispersed cell suspensions of Chondromyces crocatus, which is essential for quantitative studies of fruiting body formation. Cells of C. crocatus have a tendency to aggregate in liquid, hindering quantitative studies. However, cells grown on casitone-yeast extract agar plates, containing 3% agar, allowed the preparation of well-dispersed cell suspensions. Cell suspensions at a concentration of
, obtained by using this method, developed typical C. crocatus fruiting bodies when placed as
spots on agar plates with no nutrient supplementation. The addition of nutrients such as casitone altered or inhibited fruiting body formation. Fruiting body branch formation increased with increasing agar content. Under optimum conditions, the formation of fruiting body structure in C. crocatus KYC2823 was completed within 24 h.
Iron Containing Superoxide Dismutase of Streptomyces subrutilus P5 Increases Bacterial Heavy Metal Resistance by Sequestration
Kim, Jae-Heon ; Han, Kwang Yong ; Jung, Ho Jin ; Lee, Jungnam ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 179~184
DOI : 10.7845/kjm.2014.4053
Mitigation of heavy metal toxicity by iron containing superoxide dismutase (FeSOD) of Streptomyces subrutilus P5 was investigated. For E. coli
, the survival rate in the presence of 0.1 mM lead ions was only 7% after 120 min; however, with the addition of
of purified native FeSOD the survival rate increased to 39%. This detoxification effect was also shown with 0.01 mM copper ions (survival increased from 6% to 50%), and the effect was stronger than with the use of EDTA. E. coli M15[pREP4] producing 6xHis-tagged FeSOD was constructed, and this showed an increase in survival rates throughout the incubation time; in the presence of 0.1 mM lead ions,the final increase at 60 min was from 3% to 19%. The FeSOD absorbed about 123 g-atom lead per subunit; therefore, we suggest that FeSOD could sequestrate toxic heavy metals to enhance bacterial survival against heavy metal contamination.
Prevalence and Molecular Characterization of Quinolone Antibiotic Resistance in Escherichia coli Isolates from Raw Bulk Milk in Gyeonggi-do
Kang, Sowon ; Lee, Sangjin ; Choi, Sungsook ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 185~190
DOI : 10.7845/kjm.2014.4036
The aim of this study was to investigate the prevalence of quinolone resistant E. coli from raw bulk milk and to characterize the resistance determinants. In this study, the gyrA, gyrB, parC, and parE quinolone resistance determining regions (QRDR) were sequenced from quinolone resistant E. coli isolates. Also, the presence of plasmid-mediated quinolone resistance (PMQR) and the expression of efflux pump genes based on quantitative real-time PCR (qRT-PCR) were investigated. Of the 487 coliform bacteria, 9 strains showed nalidixic acid resistance, and 6 of the 9 nalidixic acid resistant isolates were also ciprofloxacin resistant. These 9 strains had a single mutation at codon 83 (S83L) in gyrA, 2 of them had double mutations at codon 83 and 87 (S83L and D87N) in gyrA and 3 of the 9 isolates had single mutations at codon 80 (S80I) in parC. None of the 9 isolates harbored PMQR determinants. Compared with wild-type E. coli ATCC 25922, an over-expression of the acrB gene (2.15-5.74 fold), encoding the pump component of the AcrAB-TolC efflux pump was observed in 4 of 6 ciprofloxacin resistant isolates. This study identified the quinolone resistance mechanism of E. coli isolated from raw milk samples in Gyeonggi-do.
Characteristics of Microbial Community Structures of the Methane Hydrate Sediments in the Ulleung Basin, East Sea of Korea
Shin, Ji-Hye ; Nam, Ji-Hyun ; Lee, Jin-Woo ; Lee, Dong-Hun ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 191~200
DOI : 10.7845/kjm.2014.4033
Gas hydrates play a significant role in the global carbon cycle and climate change because methane, a greenhouse gas, can be released from the dissociation of gas hydrate. Anaerobic oxidation of methane (AOM) is an important process that consumes more than 90% of the methane released into the hydrosphere and atmosphere. In this study, the microbial community associated with the methane gas hydrate sediment in the Ulleung basin, East Sea of Korea (UBGH) was analyzed by phylogenetic analysis of the mcrA and 16S rRNA gene libraries. A vertical stratification of the dominating anaerobic methane oxidizer (ANME)-1 group was observed at the surface and the sulfate methane transition zone (SMTZ). The ANME-2c group was found to be dominant in the high methane layer. The archaea of marine benthic group B, which is commonly observed in the AOM region, accounted for more than 50% of the identifications in all sediments. Nitrate reducing bacteria were predominant at SMTZ (Halomonas: 56.5%) and high methane layer (Achromobacter: 52.6%), while sulfate reducing bacteria were not found in UBGH sediments. These results suggest that the AOM process may be carried out by a syntrophic consortium of ANME and nitrate reducing bacteria in the gas hydrates of the Ulleung Basin of the East Sea.
Biological Control of Anthracnose (Colletotrichum gloeosporioides) in Red Pepper by Bacillus sp. CS-52
Kwon, Joung-Ja ; Lee, Jung-Bok ; Kim, Beam-Soo ; Lee, Eun-Ho ; Kang, Kyeong-Muk ; Shim, Jang-Sub ; Joo, Woo-Hong ; Jeon, Chun-Pyo ; Kwon, Gi-Seok ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 201~209
DOI : 10.7845/kjm.2014.4035
This study was carried out in order to develop a biological control of anthracnose of red pepper caused by fungal pathogens. In particular, this study focuses on the Colletotrichum species, which includes important fungal pathogens causing a great deal of damage to red pepper. Antagonistic bacteria were isolated from the soil of pepper fields, which were then tested for biocontrol activity against the Colletotrichum gloeosporioides anthracnose pathogen of pepper. Based on the 16S rRNA sequence analysis, the isolated bacterial strain CS-52 was identical to Bacillus sp. The culture broth of Bacillus sp. CS-52 had antifungal activity toward the hyphae and spores of C. gloeosporioides. Moreover, the substances with antifungal activity were optimized when Bacillus sp. CS-52 was grown aerobically in a medium composed of 0.5% glucose, 0.7%
, and 0.15% yeast extract at
. The inhibition of spore formation resulting from cellulase, siderophores, and indole-3-acetic acid (IAA), were produced at 24 h, 48 h, and 72 h, respectively. Bacillus sp. CS-52 also exhibited its potent fungicidal activity against anthracnose in an in vivo test, at a level of 70% when compared to chemical fungicides. These results identified substances with antifungal activity produced by Bacillus sp. CS-52 for the biological control of major plant pathogens in red pepper. Further studies will investigate the synergistic effect promoting better growth and antifungal activity by the formulation of substances with antifungal activity.
Characterization of a Small Cryptic Plasmid from Pseudomonas nitroreducens Strain TX1
Nguyen, Ngoc Tuan ; Lee, Kyoung ; Kang, Ju Beom ; Huang, Shir-Ly ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 210~215
DOI : 10.7845/kjm.2014.4038
Pseudomonas nitroreducens TX1 was isolated from a rice field drainage in Taiwan. The bacterium is of special interest because of its capability to use a group of nonionic surfactants such as alkylphenol polyethoxylates even at high concentrations as a sole carbon source. In this study, a small cryptic circular plasmid, pTX1, was characterized from P. nitroreducens TX1. It is 2,286 bp in length with a GC content of 63.3% and harbors three open reading frames,
and functionally unidentified ORF1 and ORF2. The predicted
gene product is homologous to Rep proteins of plasmids belonging to the pC194/pUB110 family, which is predominantly found in Gram-positive bacteria and is known to replicate by the rolling-circle mechanism. The copy number of pTX1 was estimated to be about 150 in each cell. Based on the genetic fingerprints and comparison with other plasmids, it is concluded that pTX1 replicates by a rolling circle mechanism which is rarely found for Pseudomonas plasmids.
Stability Traits of Probiotics Isolated from Korean on Spices and Propolis
Lee, Do Kyung ; Park, Jae Eun ; Kim, Kyung Tae ; Do, Myung Jin ; Chung, Myung Jun ; Lee, Gwa Soo ; Kim, Jin Eung ; Ha, Nam Joo ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 216~222
DOI : 10.7845/kjm.2014.4041
their survival rates could be affected by various factors such as diet, stress, senescence, and antibiotics. This study was performed to evaluate the influence of various spices (garlic, ginger, scallion, onion, Chungyang red pepper, and red pepper) which have antimicrobial properties and used frequently in Korean diet, and propolis on probiotics isolated from Koreans. As a result, most Korean probiotic strains were resistant to all spices tested and propolis, and the growth rates of some Korean probiotic strains (Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophiles) were even increased by specific spices or propolis. But on the other hand, the growth rates of most of european probiotic strains were reduced by various spices or propolis, and the growth rates of a few european probiotic strains (L. helveticus, S. thermophiles) were greatly decreased in the presence of specific spices. Likewise, all commercial probiotic products including Korean probiotic strains were rarely affected by spices tested. However, european probiotic product tended to be greatly reduced by garlic, onion, scallion, and propolis. Therefore, these results indicate that probiotic strains isolated from Korean have the strong viability and resistance to various spices with antimicrobial properties, so that they might be appropriate for Korean intestine.
Ethanol Extracts of Chungkookjang Stimulate the Proliferation and Migration of Human Umbilical Vascular Endothelial Cells
Hwang, Jae Sung ; Sung, Dae Il ; Lee, Whan Myung ; Chung, Young Shin ; Kim, Han Bok ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 223~226
DOI : 10.7845/kjm.2014.4037
In the fermented soybean product known as "chungkookjang", diverse bioactive compounds are produced when the soybean proteins are degraded during fermentation. Vascular endothelial cells (EC) are crucial in vein function and the formation of new vessels. A treatment to stimulate formation of new blood vessels is needed in cerebrovascular diseases that lead to ischaemic stroke and heart attack, as well as for diabetic ulcers. VEGF (Vascular Endothelial Growth Factor) simulates EC formation. The effect of Chungkookjang ethanol extract (CEE) on the proliferation of EC was studied. CEE (100,
) and boiled CEE were as effective as VEGF (10 ng/ml) for the proliferation of human umbilical vascular endothelial cells (HUVEC). The effect of CEE on the migration of HUVEC was investigated using sprout analysis. CEE (
) was as effective as VEGF (10 ng/ml) for the migration of HUVEC. Isolation of specific peptides influencing the growth and migration of EC is needed.
Effect of Acetic Acid Concentration and Mixed Culture of Lactic Acid Bacteria on Producing Bacterial Cellulose Using Gluconacetobacter sp. gel_SEA623-2
Kim, Kyung min ; Kim, Jihyeon ; Yang, Kyong Wol ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 227~232
DOI : 10.7845/kjm.2014.4062
In this study, Gluconacetobacter sp. gel_SEA623-2 isolated from citrus that produces bacterial cellulose was used to examine the effect of initial concentration of acetic acid and mixed culture inoculated with Lactobacillus plantarum KCCM 80077 on productivity of bacterial cellulose. In mixed culture added with 0.5% acetic acid, the viable cell count increased from
after 14 days of culture, and total acidity was about 0.3% higher than single culture added with 0.5% acetic acid, which implies that additional lactic acid was produced by L. plantarum KCCM 80077. In single culture, although bacterial cellulose productivity was higher when the initial concentrations of acetic acid were 0.0% and 0.5%, than when it was 1.0%, there was no significant difference. However, in mixed culture, adding 0.5% acetic acid resulted in dry weight of
and thickness of
, showing a significant difference from that of single culture added with 1% acetic acid,
Characterization of Lactobacillus brevis JBE 30 as a Starter for the Brewing of Traditional Liquor
Heo, Jun ; Ryu, MyeongSeon ; Jeon, SaeBom ; Oh, HyeonHwa ; Kim, Young Sang ; Jeong, DoYoun ; Uhm, Tai-Boong ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 233~238
DOI : 10.7845/kjm.2014.4065
For the collection of starters suitable for the brewing of traditional liquor, an alcohol-resistant strain of lactic acid bacteria with low level of acid production was isolated from traditional fermented soybean lumps. The strain named as JBE 30 was identified as Lactobacillus brevis by 16S rRNA sequence analysis and additional biochemical tests. The strain could grow well at a MRS medium containing 8% (v/v) ethanol for 96 h of cultivation at
. The final pH after cultivation was 4.5. It also inhibited the growth of food spoilage and pathogenic bacteria including Escherichia coli, Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Micrococcus luteus, and Pseudomonas aeruginosa. These results showed that Lactobacillus brevis JBE 30 could be used as a promising starter in brewing process of traditional liquor.
Effect of Truncation of 38 Amino Acids in N-terminal Region of ErmSF, a MLS
Antibiotic Resistance Factor Protein, on Enzymatic Activity
Lee, Hak Jin ; Jin, Hyung Jong ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 239~244
DOI : 10.7845/kjm.2014.4051
ErmSF is one of the four antibiotic resistance factor proteins expressed by Streptomyces fradiae, antibiotic tylosin producer, which renders
(macrolide-lincosamide-streptogramin B) antibiotic resistance through dimethylating A2058 of 23S rRNA, thereby reducing the affinity of antibiotic to ribosome. Unlike other Erm proteins, ErmSF harbors long N-terminal end region. To investigate its role in enzyme activity, mutant ErmSF deleted of 1-38 amino acids was overexpressed and activity in vivo and in vitro was observed. In vitro enzymatic assay showed that mutant protein exhibited reduced activity by 20% compared to the wild type enzyme. Due to the reduced activity of the mutant protein, cells expressing mutant protein showed weaker resistance to erythromycin than cells with wild type enzyme. Presumably, the decrease in enzyme activity was caused by the hindrance in substrate binding and (or) product release, not by defect in the methyl group transfer occurred in active site.
Phenotypic Characteristics of Pseudomonas syringae pv. actinidiae Strains from Different Geographic Origins
Choi, Eun Jin ; Lee, Young Sun ; Kim, Gyoung Hee ; Koh, Young Jin ; Jung, Jae Sung ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 245~248
DOI : 10.7845/kjm.2014.4039
Pseudomonas syringae pv. actinidiae is the causal agent of bacterial canker in kiwifruit (genus Actinidia). Multilocus sequence analysis of seven housekeeping and 11 type III effector genes differentiated the virulent P. syringae pv. actinidiae isolates worldwide into three groups designated as Psa1-Psa3. In this work, a total of 12 P. syringae pv. Actinidiae strains, including three Psa1, three Psa2, three Psa3 strains isolated from Korea and three Psa3 strains from Italy, were compared based on their phenotypic properties. Strains with different geographic origins had unique growth patterns as demonstrated by growth rate at several temperatures; all tested strains exhibited maximum growth at temperatures below
, while the growth of Psa3 strains was completely inhibited above
. Psa3 strains isolated from Korea had longer lag phases than the Psa3 strains from Italy. The Psa2 strains were different from Psa1 and Psa3 strains in the API 20NE test, in which the Psa2 strains could not utilize potassium gluconate, capric acid and trisodium citrate. Psa3 strains isolated from Korea could hydrolyze esculin. The API ZYM test showed that
-glucosidase activity was detected only from Psa3 strains. The strains belonging to the three Psa groups differed with regard to their susceptibility to ampicillin, novobiocin, and oleandomycin.
Effects of spThoc7 Deletion on Growth and mRNA Export in Fission Yeast
Koh, Eun-Jin ; Yoon, Jin Ho ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 249~253
DOI : 10.7845/kjm.2014.4055
THOC7/Mft1 is a member of the THO complex that is an evolutionally conserved assembly connecting transcription elongation with mRNP packaging and mRNA export. In fission yeast Schizosaccharomyces pombe, an ortholog (spThoc7) of THOC7/Mft1 was isolated by partial complementation of the lethality in synthetic lethal mutant, SLRsm1. A deletion mutant in a diploid strain was constructed by replacing one of spThoc7-coding region with an
gene using one-step gene disruption method. Tetrad analysis showed that the spthoc7 is nonessential for growth. But the
null mutant showed slight defects of both growth and mRNA export. And the functional spThoc7-GFP protein is localized mainly in the nucleus. These results suggest that spThoc7 is also involved in mRNA export from the nucleus to cytoplasm.
Isolation and Characterization of Sulfate- and Sulfur-reducing Bacteria from Woopo Wetland, Sunchun Bay, and Tidal Flat of Yellow Sea
Kim, So-Jeong ; Min, Ui-Gi ; Hong, Heeji ; Kim, Jong-Geol ; Jung, Man-Young ; Cha, In-Tae ; Rhee, Sung-Keun ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 254~260
DOI : 10.7845/kjm.2014.4054
Sulfur compound includes major electron acceptors for anaerobic respiration. In this study, cultivation-based study on sulfate- and sulfur-reducing bacteria of various wetlands of Korea was attempted. To isolate sulfate- and sulfur-reducing bacteria, anaerobic roll tube method was used to obtain typical black colonies of sulfate- and sulfur-reducing bacteria. Total 11 strains obtained were tentatively identified based on comparative 16S rDNA similarity and physiological property analysis. All sulfate-reducing bacteria (8 strains) belonged to genus Desulfovibrio with >99% 16S rDNA similarities. Three sulfur reducing bacteria were also isolated: two and one isolates were affiliated with Sulfurospirillum and Desulfitobacterium, respectively. These sulfate- and sulfur-reducing bacteria were able to utilize lactate and pyruvate and sulfite and thiosulfate as common electron donors and electron acceptors, respectively. This case study will provide fundamental information for obtaining useful indigenous sulfate- and sulfur-reducing bacteria from Korean wetlands employing various combinations of cultivation conditions.
Peptide H Reduces IL-6 Expression in Human Breast Cancer MDA-MB-231 Cells
Sung, Dae Il ; Park, Jameon ; Kim, Han Bok ;
The Korean Journal of Microbiology, volume 50, issue 3, 2014, Pages 261~263
DOI : 10.7845/kjm.2014.4048
Chronic inflammation is involved in cancers, rheumatoid arthritis, and Crohn's disease. Inerleukin-6 (IL-6) plays major roles in inflammation. Chungkookjang, fermented soybean contains diverse peptides produced by cleavage of soybean proteins. The peptides can be bioactive compounds. Peptide (Gly-Val-Tyr-Tyr-Met-Tyr was purified from Chungkookjang, and modified to be 6mer H, Glu-Val-Tyr-Tyr-Met-Tyr (EVYYMY). Peptide H's activity to suppress IL-6 expression in a human breast cancer cell, MDA-MB-231 was determined. IL-6 Expression was reduced in the cell treated with peptide H 25 times less than controls which were not treated with peptide H. Proliferation of MDA-MB-231 cells was inhibited by peptide H, which is concentration-dependent. Blocking of IL-6 signals is known to be effective in reducing inflammation in rheumatoid arthritis, Crohn's disease, and cancers. Since peptide H can reduce inflammatory IL-6 expression, application of this study will contribute to drug development for diseases which are caused by excessive IL-6.