• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.919-927
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• 2007

Antagonistic fluorescent pseudomonads isolated from rhizospheric soil of rice were characterized by 16S rRNA amplicon and fatty acid methyl ester (FAME) analyses. Antagonistic isolates were grown in the fermentation media, and production of antibiotics was confirmed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Production of fungal cell-wall-degrading enzymes such as protease, cellulase, pectinase, and chitinase was determined. Dendrogram based on the major and differentiating fatty acids resulted into 5 clusters, viz., cluster I (P. pseudoalcaligenes group), cluster II (P. plecoglossicida group), cluster III (P. fluorescens group), cluster IV (P. aeruginosa group), and cluster V (P. putida group). Characteristic presence of high relative proportions of cyclopropane (17:0 CYCLO w7c) was observed in antagonistic bacteria. Data revealed biodiversity among antagonistic fluorescent pseudomonads associated with the rice rhizosphere. Results presented in this study will help to identify the antagonistic isolates and to determine their mechanisms that mediate antagonism against fungal pathogens of rice.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.508-511
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• 2000

In situ hybridization with fluorescent oligonucleotides(FISH) was used to detect and localize microorganisms in the granules of lab-scale upflow anaerobic sludge blanket(UASB) reactors. An UASB reactor was seeded with mesophilically-grown($35^{\circ}\;C$) granular sludge, and thermophilically($55^{\circ}\;C$) operated by feeding with a synthetic wastewater. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Eubacteria, Archaeabacteria, and specific phylogenetic groups of methanogens. FISH clearly showed the layed structure of thermophilic granules, which was consisted of outer bacterial cells and inner archaeal cells. Methanoseata-, Methanosarcina-like cells were also found to be localized inside the granules. These results demonstrated FISH was useful in studying the spatial organizations of methanogens and in situ morphologies and metabolic functions in thermophilic granular sludges.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.93-96
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• 2004

생태학, 환경공학, 임상진단 둥 여러 생물학 분야에서 미생물의 다양성 연구의 중요성이 대두되고 그 연구가 점증하고 있다. 특히 16S rRNA를 분자지표로한 DNA 염기서열 분석방법이 널리 사용되고 있다. 본 논문에서는 16S rRNA의 염기서열 분석과정을 각 단계별로 자동화하고, 생물학자들의 결과 판단이나 사용상의 편의를 도모하기 위하여 웹기반의 미생물 다양성 분석 어플리케이션을 개발하였다. 개발을 위하여 단계별 자동화 및 인터페이스 개발에 적합한 폴더 프로세스-필터 모델을 고안하고 적용하였다. 제공되는 생물정보분석도구는 서열입력, 서열방향교정, 다중서열정렬 및 가시화, 서열동정 등의 분석등이 있으며, 각 결과는 계통분류도구와 호환가능하도록 하였다. 또한 신생아의 장내 세균총에 대한 분석을 수행하여 개발된 도구의 유용성을 확인하였다. 개발된 웹 에플리케이션은 리눅스 시스템 상에서 Perl 과 CGI를 이용하였으며, http: //home.pusan.ac.kr/~genome/tools/rat.htm으로 접속하여 사용할 수 있다.

• Korean journal of applied entomology
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• v.57 no.1
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• pp.39-42
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• 2018

Conwentzia is a newly recorded genus in Korea, based on C. pineticola. A brief description, photos of adult and male genitalia, and 16S rRNA and COI sequences of the species are provided.

• Biomedical Science Letters
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• v.19 no.3
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• pp.280-283
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• 2013

Leuconostoc spp. is intrinsically resistant against vancomycin and rarely causes the infection in immunocompromised patients. In this report, we describe a fatal case of Leuconostoc lactis bacteremia in a patient with biliary tract stent insertion to resolve the biliary tract obstruction by multiple pseudocysts in the pancreatic head region. Leuconostic lactis isolated from the blood of the patients was confirmed by 16S rRNA sequencing and this isolate was susceptible against most antibiotics, including levofloxacin, penicillin, erythromycin and cefotaxime except vancomycin. The septic shock and multi-organ failure was abruptly progressed due to delayed use of adequate antibiotic. Using vancomycin as the empirical antibiotics in a bacteremic patient by Gram positive cocci, the treatment failures by the isolates with intrinsic resistance against vancomycin have to be considered. In addition, the prompt and accurate identification of Leuconostoc spp. are very important to select the adequate antibiotics.

• Ocean Science Journal
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• v.41 no.2
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• pp.113-119
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• 2006

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1571-1576
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• 2010

Two bacterial strains designated as CT2 and CT5 were isolated from highly alkaline cement samples using the enrichment culture technique. On the basis of various physiological tests and 16S rRNA sequence analysis, the bacteria were identified as Bacillus species. The urease production was 575.87 U/ml and 670.71 U/ml for CT2 and CT5, respectively. Calcite constituted 27.6% and 31% of the total weight of sand samples plugged by CT2 and CT5, respectively. Scanning electron micrography analysis revealed the direct involvement of these isolates in calcite precipitation. This is the first report of the isolation and identification of Bacillus species from cement. Based on the ability of these bacteria to tolerate the extreme environment of cement, they have potential to be used in remediating the cracks and fissures in various building or concrete structures.

• Journal of Microbiology
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• v.45 no.3
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• pp.272-274
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• 2007

During May to July 2004, three strains of Providencia spp. with multidrug-resistance (MDR) were isolated from urinary specimen of three patients hospitalized with a same hospital room. By PCR analysis, all three strains have been found to carry both VIM-2 type $metallo-{\beta}-lactamase$ gene and PER-1 type extended spectrum ${\beta}-lactamase$ gene. One out of three strains carried additional resistance gene, armA, 16S rRNA methylase gene responsible for high level resistance to aminoglycosides. To our knowledge, this is the first report on the identification of Providencia spp. simultaneously carrying $bla_{VIM-2},\;bla_{PER-1}$, and armA genes.

• Parasites, Hosts and Diseases
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• v.57 no.1
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• pp.69-73
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• 2019

In a population-based study with 4 years of follow up, we evaluated the prevalence of Coxiella burnetii in cattle on Ulleung Island, Korea. In this study, the rates of C. burnetii infection in cattle on Ulleung Island were determined by PCR and were found to be 0.3-1.0% in the period 2011-2014. All 17 C. burnetii partial 16S rRNA gene sequences from PCR-positive cattle were identical and 2 geographic representatives were included in our analysis. The nucleotide sequences of the 2 samples showed high (98.4-100%) identity with C. burnetii sequences obtained from the GenBank. In this long-term tracking study, the number of cattle positive for C. burnetii on Ulleung Island was low. To prevent the transmission of C. burnetii on Ulleung Island, control strategy should include biosecurity improvement in surveillance, livestock management, administering suitable tests before purchasing animals to detect C. burnetii shedders, and restricting movements between herds.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.215-222
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• 2023

In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.