• 한국응용곤충학회지
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• 제37권1호
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• pp.23-30
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• 1998

DNA의 제한요소단편 다형현상(RFLP)이 유전변이 연구에 널리 이용되고 있다. 본 연구는 파밤나방(Spodoptera exigua(H bner)) 미토콘드리아 DNA(mtDNA)의 RFLP방법을 개발하기 위해 게놈 크기 측정 및 PCR primer들을 선발하였다. 파밤나방의 mtDNA 전체크기는 약 16kb였다. 대부분 곤충 mtDNA에 적합하게 구성된 (Simon et al., 1994)29개 promer들중 21개가 파밤나방의 mtDNA증폭에 적합했다. 이들 primer들을 이용하여 여러 유전자 영역(CO-I, CO-II, Cyt-B, ND-1, 12S rRNA, 16S rRNA 및 일부 tRNA)의 일분 또는 전체를 포함하는 유전자 절편을 증폭시켰다. 일반적으로 다형을 보이는 primer조합을 중심으로 4염기 제한부위를 인식하는 8종의 제한 효소를 통해 분석된 PCR-RFLP는 서로 다은 지역(안동, 경산, 순천) 집단들간에 제한부위에 있어서 차이가 없었으나 일부 영역에서는 길이 차이를 보여 유용한 유전지표로서의 가능성을 제시했다.

• Journal of Animal Science and Technology
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• 제47권3호
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• pp.465-474
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• 2005

A two-step broad-range PCR method detecting gram-negative bacteria at the level as low as 2 CFU was developed by using primers of GNFI and GNRI and then semi-nested primer of GNF2 and GNRI. The nucleotide sequences of the primers were determined based on l6S rRNA gene. The DNA fragments of 1173 bp and 169 bp were amplified in one-step PCRs with primer sets of GNFI-GNRI and GNF2-GNRl, respectively, using template DNA from seven strains of gram-negative bacteria including Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas spp., and Acinetobacter baumaii but not from Achromobacter lyticus, Alca/igens faecalis, and five strains of gram-positive bacteria. DNA fragments of 180 bp were amplified from LTLT-pasteurized milk and UHf-pasteurized milk in the two-step PCR. The DNA fragments were amplified from LTLT-pasteurized milk which was added with Pseudomonas j/uorescens and subsequently heated at 65 $^{\circ}C$, 80 $^{\circ}C$, and 100 $^{\circ}C$ for 30 min but they were not amplified from the milk autoclaved at 121$^{\circ}C$ for 15 min. It was suggested in PCR that Pseudomonas fluorescens heated at 65 $^{\circ}C$ for 30 min in milk was more sensitive to DNase treatment than viable bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.179-186
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• 2014

This study aimed to investigate the diversity of the Butyrivibrio group bacteria in goat rumen and its response to garlic oil (GO) supplementation as revealed by molecular analysis of cloned 16S rRNA genes. Six wethers fitted with ruminal fistulas were assigned to two groups for a cross-over design with 28-d experimental period and 14-d interval. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents were used for DNA extraction collected before morning feeding on d 28. A total bacterial clone library was firstly constructed by nearly full-length 16S rRNA gene cloned sequences using universal primers. The resulting plasmids selected by Butyrivibrio-specific primers were used to construct a Butyrivibrio group-specific bacterial clone library. Butyrivibrio group represented 12.98% and 10.95% of total bacteria in control and GO group, respectively. In libraries, clones were classified to the genus Pseudobutyrivibrio, Butyrivibrio and others within the family Lachnospiraceae. Additionally, some specific clones were observed in GO group, being classified to the genus Ruminococcus and others within the family Ruminococcaceae. Based on the criterion that the similarity was 97% or greater with database sequences, there were 29.73% and 18.42% of clones identified as known isolates (i.e. B. proteoclasticus and Ps. ruminis) in control and GO groups, respectively. Further clones identified as B. fibrisolvens (5.41%) and R. flavefaciens (7.89%) were specifically found in control and GO groups, respectively. The majority of clones resembled Ps. ruminis (98% to 99% similarity), except for Lachnospiraceae bacteria (87% to 92% similarity) in the two libraries. The two clone libraries also appeared different in Shannon diversity index (control 2.47 and GO group 2.91). Our results indicated that the Butyrivibrio group bacteria had a complex community with considerable unknown species in the goat rumen.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권3호
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• pp.199-204
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• 2003

Among 59 Korean isolated, 20 were confirmed as members of the genus Bifidobaferium species based on gram staining, microscopic examination of cell morphology and the TLC method, The oxygen tolerance and antioxidative activities of these 20 Bifidobacterium strains and 5 standard Bifidobaferium strains were tested. All the strains demonstrated antioxidative activities as regards inhibiting linoleic acid peroxidation. The antioxidative activities of isolated and standard strains were found to range from 10.7-46.4% and from 10.7-22.2%, respectively. In addition, all tested strains exhibited a Scavenging ability on DPPH free radicals, range from 15-41% for the isolated strains and 8.3-22% for the standard strain. Accordingly. the isolated Bifidobarterium strains demonstrated higher antioxidative artivities than the 5 standa rd Bifidobarterium strains. On the base of grades for each test, HJL 7511 was identified 35 the best strain, followed by HJL 7501. 2 strains were identified with Polymerase Chain Reaction (PCR) assay using group-specific primers designed from the nucleotide Sequences of the 16S rRNA and internal transcribed spacer (ITS) regions of the Bifidobacteria. Based on the Sequencing results, HJL 7511 and HJL 7501 were identified as Bifidobacterium infantis.

• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1290-1297
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• 2008

To investigate the diversities of Accumulibacter phosphatis and its polyhydroxyalkanoate (PHA) synthase gene (phaC) in enhanced biological phosphorus removal (EBPR) sludge, an acetate-fed sequencing batch reactor was operated. Analysis of microbial communities using fluorescence in situ hybridization and 16S rRNA gene clone libraries showed that the population of Accumulibacter phosphatis in the EBPR sludge comprised more than 50% of total bacteria, and was clearly divided into two subgroups with about 97.5% sequence identity of the 16S rRNA genes. PAO phaC primers targeting the phaC genes of Accumulibacter phosphatis were designed and applied to retrieve fragments of putative phaC homologs of Accumulibacter phosphatis from EBPR sludge. PAO phaC primers targeting $G_{1PAO},\;G_{2PAO},\;and\;G_{3PAO}$ groups produced PCR amplicons successfully; the resulting sequences of the phaC gene homologs were diverse, and were distantly related to metagenomic phaC sequences of Accumulibacter phosphatis with 75-98% DNA sequence identities. Degenerate NPAO (non-PAO) phaC primers targeting phaC genes of non-Accumulibacter phosphatis bacteria were also designed and applied to the EBPR sludge. Twenty-four phaC homologs retrieved from NPAO phaC primers were different from the phaC gene homologs derived from Accumulibacter phosphatis, which suggests that the PAO phaC primers were specific for the amplification of phaC gene homologs of Accumulibacter phosphatis, and the putative phaC gene homologs by PAO phaC primers were derived from Accumulibacter phosphatis in the EBPR sludge. Among 24 phaC homologs, a phaC homolog (GINPAO-2), which was dominant in the NPAO phaC clone library, showed the strongest signal in slot hybridization and shared approximately 60% nucleotide identity with the $G_{4PAO}$ group of Accumulibacter phosphatis, which suggests that GINPAO-2 might be derived from Accumulibacter phosphatis. In conclusion, analyses of the 16S rRNA and phaC genes showed that Accumulibacter phosphatis might be phylogenetically and metabolically diverse.

• 대한의생명과학회지
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• 제26권3호
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• pp.149-156
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• 2020

We developed a simple and rapid method for detecting vancomycin resistance genes, such as vanA and vanB, using loop-mediated isothermal amplification (LAMP). To identify not only vancomycin resistance genes, but also the genus Enterococcus, primers were designed for vanA, vanB, and 16S rRNA. Screening for vancomycin susceptibility in Enterococcus was performed using Etest (bioMérieux Inc). The results of the LAMP assay were compared to those of real-time RT-PCR. The optimal conditions for the LAMP assay were 65℃ for 60 min. The detection limits of the LAMP assay for vanA, and vanB were 2 × 10² copies/reaction. Compared to RT-PCR, the sensitivities and specificities of LAMP for 16S rRNA, vanA, and vanB were 100/100%, 100/100%, and 100/100%, respectively. The vanA genotype-vanB phenotype accounted for 57.5% (46/80) of the vancomycin-resistant Enterococci samples collected from 2016 to 2019. In conclusion, the LAMP assay developed in this study showed high sensitivity and specificity for vancomycin-resistant genes. Moreover, due to the simplicity and rapidity of the LAMP assay, its use can be very useful in clinical microbiology laboratories.

• Journal of Microbiology
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• 제38권1호
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• pp.11-17
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• 2000

A new method was developed for the rapid analysis of diverse bacterial species in the natural environment. Our method is based on PCR-single-strands-conformation polymorphism (PCR-SSCP) and selective isolation technique of single-stranded DNA. Variable V3 fragments of 16S rDNA were amplified by PCR with bacterial 16S rDNA primers, where one of the primers was biotinylated at the 5'-end. The biotinylated strands of the PCR products were selectively isolated by using streptavidin paramagnetic particles and a magnetic stand, to prevent SSCP analysis producing heteroduplexes from heterogeneous DNA samples. The selected strands were separated by electrophoresis on a polyacrylamide gel, and detected by silver staining. Analysis of PCR products from 8 bacterial strains demonstrated their characteristic DNA band patterns. In addition, changes in the structure of the bacterial community and species diversity in the microcosm treated with phenol could be monitored. After 3 weeks of incubation, phenol and its intermediate, 2-hydroxy-muconic-semialdehyde, were degraded by indigenous bacteria. These dominating bacterial populations were identified as strong bands on an SSCP gel. Therefore, this study provides useful tools for microbial community analysis of natural habitats.

• 한국식품위생안전성학회지
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• 제30권1호
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• pp.43-50
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• 2015

본 연구에서는 오징어류에 해당하는 대왕오징어, 오징어, 문어, 한치 및 이를 이용한 가공식품에 대해서 분자생물학적 기법을 활용한 시험법을 검토하였다. 시료 중 원료성분 확인을 위하여 오징어류 4종에 대해 최적의 종 특이 프라이머를 디자인하였으며, 시료로부터 직접 genomic DNA를 추출하여 PCR을 실시하였다. PCR 수행과정에서 반응을 저해하는 염 성분을 제거하기 위하여 증류수를 이용하여 3~4회 세척 후 PCR을 실시한 결과, Single PCR의 경우 대왕오징어(552 bp), 오징어(463 bp), 문어(247 bp), 한치(354 bp)에 해당하는 종 특이적인 증폭산물을 확인하였으며, Multiplex PCR 의 경우 서로 다른 종 사이의 교차반응없이 동시다발적으로 증폭이 일어남을 확인할 수 있었다. 또한 이들 4종에 대해 PCR 민감도를 조사한 결과, 모두 약 $0.1ng/{\mu}l$의 농도까지 검출이 가능함을 확인하였으며 multiplex PCR의 경우 약 $0.25ng/{\mu}l$의 농도까지 검출이 가능함을 확인하였다. 이를 이용하여 오징어류가 함유된 수산물 가공식품 8건에 대해 적용성을 검토한 결과, 모든 시료에서 유효한 결과를 확인할 수 있었다. 따라서 본 연구에서 제작된 오징어류 4종에 대한 종 특이적 프라이머는 생물 상태뿐만 아니라 수산물 가공식품에 대해서도 이를 판별할 수 있어 식품안전관리에 활용할 수 있을 것으로 기대된다.

• 미생물학회지
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• 제45권1호
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• pp.26-31
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• 2009

우리나라의 전통 발효 식품인 젓갈로부터 배양 분리법과 분자생물학적 분석법을 이용하여 원핵 세균 군집을 분석하고, 신규 미생물 분리를 목표로 하였다. 젓갈은 생산 지역과 주재료를 고려하여 17 종을 선정하였으며, 이들 젓갈 시료를 적정 희석배수로 희석하여 12종류의 미생물 선택배지에 도말, 배양한 후 나타난 집락(colony)을 형태학적 특성에 따라 무작위로 308개를 선정하여 분리하였다. 순수 분리된 미생물은 PCR 방법을 이용하여 16S rRNA 유전자의 염기서열을 분석한 후, 기존에 보고된 미생물 database와 비교함으로서 17종의 젓갈 내 미생물 군집을 확인하였다. 젓갈의 발효 및 숙성 과정에 관여하는 lactic acid bacteria (Leuconostoc 속, Weisella 속, Lactococcus 속, Lactobacillus 속, Carnobacterium 속, Marinilactibacillus 속, Tetragenococcus 속)와 Bacillus 속, Pseudomonas 속, Micrococcus 속, Brevibacterium 속, Microbacterium 속과 Kocuria 속이 17가지 젓갈에서 광범위하게 분리되었으며, Salinicoccus 속, Halomonas 속, Cobetia 속, Lentibacillus 속, Paracoccus 속, Psychrobacter 속이 소수 분리되었다. 또한 분리된 미생물의 계통학적 분석을 통하여 기존에 보고된 적이 없는 신규 미생물 14종을 분리하였다.

• Genomics & Informatics
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• 제21권4호
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• pp.52.1-52.10
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• 2023

Accurate and efficient microbial diagnosis is crucial for effective molecular diagnostics, especially in the field of human healthcare. The gold standard equipment widely employed for detecting specific microorganisms in molecular diagnosis is quantitative real-time polymerase chain reaction (qRT-PCR). However, its limitations in low metagenomic DNA yield samples necessitate exploring alternative approaches. Digital PCR, by quantifying the number of copies of the target sequence, provides absolute quantification results for the bacterial strain. In this study, we compared the diagnostic efficiency of qRT-PCR and digital PCR in detecting a particular bacterial strain (Staphylococcus aureus), focusing on skin-derived DNA samples. Experimentally, specific primer for S. aureus were designed at transcription elongation factor (greA) gene and the target amplicon were cloned and sequenced to validate efficiency of specificity to the greA gene of S. aureus. To quantify the absolute amount of microorganisms present on the skin, the variable region 5 (V5) of the 16S rRNA gene was used, and primers for S. aureus identification were used to relative their amount in the subject's skin. The findings demonstrate the absolute convenience and efficiency of digital PCR in microbial diagnostics. We suggest that the high sensitivity and precise quantification provided by digital PCR could be a promising tool for detecting specific microorganisms, especially in skin-derived DNA samples with low metagenomic DNA yields, and that further research and implementation is needed to improve medical practice and diagnosis.