• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1101-1108
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• 2011

The rise in global energy demand has prompted researches on developing strategies for transforming coal into a cleaner fuel. This requires isolation of microbes with the capability to degrade complex coal into simpler substrates to support methanogenesis in the coal beds. In this study, aerobic bacteria were isolated from an Indian coal bed that can solubilize and utilize coal as the sole source of carbon. The six bacterial isolates capable of growing on coal agar medium were identified on the basis of their 16S rRNA gene sequences, which clustered into two groups; Group I isolates belonged to the genus Rhizobium, whereas Group II isolates were identified as Chelatococcus species. Out of the 4 methods of whole genome fingerprinting (ERIC-PCR, REP-PCR, BOX-PCR, and RAPD), REP-PCR showed maximum differentiation among strains within each group. Only Chelatococcus strains showed the ability to solubilize and utilize coal as the sole source of carbon. On the basis of 16S rRNA gene sequence and the ability to utilize different carbon sources, the Chelatococcus strains showed maximum similarity to C. daeguensis. This is the first report showing occurrence of Rhizobium and Chelatococcus strains in an Indian coal bed, and the ability of Chelatococcus isolates to solubilize and utilize coal as a sole source of carbon for their growth.

• Quantitative Bio-Science
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• 제37권2호
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• pp.125-132
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• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.

• Journal of Microbiology
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• 제45권6호
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• pp.479-484
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• 2007

Bacterial communities at 10 cm, 100 cm, and 200 cm depths in a 100-year-old lead-zinc tailing heap were evaluated by constructing 16S rRNA gene libraries. In total, 98 operational taxonomic units (OTUs) were identified from 193 clones at a 3% sequence difference level. The OTU number and species richness decreased with the depth. Species composition was significantly different between the three libraries. Fifty-seven percent of the examined clones were Acidobacteria and 27% belonged to Proteobacteria. Other sequences included Chloroflexi, Firmicutes, Chlamydiae, Actinobacteria, Gemmatimonadetes, Nitrospira, and three unclassified OTUs. Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria were mainly distributed in the rhizosphere of naturally colonizing plants; however, Deltaproteobacteria, Acidobacteria, and Chloroflexi tended to inhabit the deeper tailings (below the 100 cm-depth).

• 대한의생명과학회지
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• 제10권4호
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• pp.333-339
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• 2004

A multiplex PCR assay targeting the yst and 16S rRNA genes of Yersinia enterocolitica was developed to specifically identify pathogenic Y. enterocolitica from pure culture. Simultaneous amplification of 145 and 416 bp fragments of the yst and 16S rRNA genes of Y. enterocolitica was obtained using the primer pairs in a single reaction. Validation of the assay was performed with the reference Yersinia strains and other members of the family Enterobacteriaceae. The defined primer pairs amplified the targeted sequence from only pathogenic Y. enterocolitica strains, whereas none of the other bacterial species yielded any amplified fragments. Within an assay time of 4 h, this assay offers a very specific, reliable, and inexpensive alternative to the conventional phenotypic assays used in clinical laboratories to identify pathogenic Y. enterocolitica.

• 미생물학회지
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• 제55권3호
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• pp.303-305
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• 2019

섬 해안가 토양에서 방선균주 Gordonia sp. MMS17-SY073를 분리하여 유전체 분석을 실시하였고, 그 결과 5,962,176 염기쌍 및 67.4%의 G + C 함량으로 이루어진 유전체 정보를 확보하였다. 유전정보 분석 결과 총 5,201개 단백질 지정 유전자, 6개 rRNA 유전자 및 45개 tRNA 유전자를 확인하였다. MMS17-SY073 균주는 16S rRNA 유전자를 이용한 분석 결과 분류학적으로 Gordonia soli의 표준균주와 가장 가까웠으며 그 유사도는 98.5%로 나타났다. MMS17-SY073 균주는 non-ribosomal peptide synthetase 유형을 비롯한 다수의 이차대사산물 생합성 유전자를 보유하고 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.67-73
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• 1998

A bacterial strain that excretes hemolysins and proteases into the growth medium was isolated from sea water and designated as KYJ 961. A nearly complete nucleotide sequence of a 16S ribosomal RNA gene from the isolate was determined following the isolation and cloning of amplified genes. On the basis of the 16S ribosomal DNA sequence data, and morphological, chemotaxonomic, and physiological characteristics, strain KYJ 961 was classified as a strain of Bacillus cereus.

• 미생물학회지
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• 제42권4호
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• pp.313-318
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• 2006

가정에서 제조된 된장으로부터 cellulase 생산균으로 분리된 고온성 WL-12는 형태적 특성, 생화학적 성질 및 16S rRNA의 염기서열에 근거하여 Bacillus licheniformis로 동정되었다. B. licheniformis WL-12의 cellulase 유전자를 클로닝하여 그 염기서열을 결정한 결과 cellulase 유전자(celA)는 517 아미노산으로 구성된 단백질을 코드하며 1,551 뉴클레오티드로 이루어졌다. 아미노산 잔기배열을 분석한 결과 WL-12의 cellulase는 활성영역과 cellulose 결합영역으로 구성되어 있었으며, glycosyl hydrolase (GH) family 5에 속하는 B. licheniformis, B. subtilis와 B. amyloliquefaciens의 cellulase와 높은 상동성을 보였다. 클론된 celA를 발현용 vector에 도입하여 B. subtilis에서 발현시켜 cellulase 최대생산성이 7.0 units/ml에 이르렀다.

• 한국응용과학기술학회지
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• 제39권5호
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• pp.605-613
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• 2022

Flavobacterium 속(genus)은 Bacteriodetes 문(phylum), Flavobacteriaceae 과(family)의 대표속(type genus)으로서, 이 속의 세균들은 황색 색소를 함유하는 그람 음성 간균이다. 이 속 세균들은 자연계의 다양한 환경에서 분리되고 있다. 황색색소를 함유하는 그람음성 간균이 경남 창원시 소재 창원대학교 교내의 연못에서 분리되었고, 이 세균은 균주 B1으로 명명되었다. 균주 B1을 생리학적, 생화학적 및 계통분석학적으로 분석한 결과, Flavobacterium 속에 속하는 것으로 결론지어졌다. 이 세균의 16S rRNA 유전자 염기서열을 BLAST로 분석해 본 결과, 다른 어떠한 세균과도 16S rRNA 유전자 염기서열의 상동성이 99.0%를 넘지 않았다. 균주 B1의 주된 지방산은 iso-C_15:0(19.6%), summed feature 3(C_16:1 ω7c and/or C_16:1 ω6c, 16.1%), iso-CC_17:0 3OH(10.2%), iso-C_15:0 3OH(8.4%) 및 iso-C_15:1 G(6.6%)인 것으로 밝혀졌는데, 이는 다른 Flavobacterium 종들의 지방산 함량과 확연한 차이가 있는 것을 알 수 있었다. 이 세균의 16S rDNA 염기서열은 genbank에 accession number OP060681로 등록되었다.

• Journal of Microbiology
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• 제40권4호
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• pp.335-339
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• 2002

Partial sequences of 16S rRNA gene of five chroococcalian blue-green algal strains, Aphanothece nidulans KCTC AG10041, Aphanothece naegelii KCTC AG10042, Microcystis aeruginosa KCTC AG10159, Microcystis ichthyoblabe KCTC AG10160, and Microcystis viridis KCTC AG10198, which were isolated from water from the Geumgang River, were determined and were inferred their phylogenetic and taxonomic positions among taxa of order Chroococcales. Most taxa of Chroococcales whose partial 16S rRNA gene sequences were aligned in this study, are clustered with other related taxa. Aphanothece nidulans KCTC AG10041 and Aphanothece naegelii KCTC AG10042 made a cluster with other European species of these genera, which supported 100% of the bootstrap trees with a very high sequence similarity (97.4-99.4%) in this study. Three strains, Microcystis aeruginosa KCTC AG10159, M. ichthyoblabe KCTC AG10160, and M. viridis KCTC AG10198, formed a cluster with other Microcystis spp. supported 100 % of the bootstrap trees with a similarity of 97.0-99.9% except for two strains. However, this phylogentic tree made no resolution among the species of Microcystis spp. The topology of the tree reconfirmed the taxonomic status of three species of Microcystis, identified in this study based on the morphology, as three colonial types of Microcystis aeruginosa com. nov. Otsuka et al. (1999c). The genera of chroococcalian cyanophytes are heterogeneously clustered in these sequence analyses. We suggest that more molecular studies on the genera of Chroococcales with reference strains, widely collected from restricted geographic or environmental ranges, get accurate taxonomic or phylogenetic determinations.

• 생명과학회지
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• 제12권2호
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• pp.158-163
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• 2002

남조류 Microcystis aeruginosa를 무균적으로 분리하기 위해 낙동강 물금지역의 수화를 멸균 증류수로 vortex 전처리를 하였으며, 세균제거 및 무균상태를 계속 유지하기 위하여 항생물질(ampicillin 150 $\mu$g/$m\ell$, neomycin 25 $\mu$g/$m\ell$)을 배지에 첨가하고, 독립 집락으로 형성시켜 오염 기회를 줄이기 위하여 0.7% agarose로 고형화시킨 CB고체배지에서 3$0^{\circ}C$, 40 $\mu$mol m$^{-2}$ s$^{-1}$ 광 조건으로 배양하였다. 그 결과 분리되어진 26개의 Microcystis aeruginosa colony 중 3개의 무균 균주만이 확보되었다. 3개의 무균균주를 16S rRNA primer를 이용하여 PCR 증폭한 결과 M. aeruginosa AF 139292와 99.5에서 100%의 상동성을 가지는 것으로 나타났다.