• Journal of Microbiology and Biotechnology
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• 제20권11호
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• pp.1592-1596
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• 2010

To verify the dominance of microorganisms in wastewater biological treatment, PCR-DGGE (denaturing gradient gel electrophoresis) was performed as a supplementary support method for screening of the dominant microorganisms from activated sludge. Results suggest that the dominant microorganisms in activated sludge are primarily responsible for strengthening its effectiveness as a biological treatment system, followed by the non-main dominant microorganisms, whereas the non-dominant microorganisms showed no effects. The degree of microbial abundance present on the profile of PCR-DGGE was in line with the treatment efficiency of augmented activated sludge with isolated cultures, suggesting that PCR-DGGE can be used as an effective supplementary method for verifying culturable dominant microorganisms in activated sludge of coking wastewater.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1303-1310
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• 2016

Although many studies on the effects of genetically modified (GM) crops on soil microorganisms have been carried out over the past decades, they have provided contradictory information, even for the same GM crop, owing to the diversity of the soil environments in which they were conducted. This inconsistency in results suggests that the effects of GM crops on soil microorganisms should be considered from many aspects. In this study, we investigated the effects of the GM drought-tolerant rice MSRB2-Bar-8, which expresses the CaMSRB2 gene, on soil microorganisms based on the culture-dependent and culture-independent methods. To this end, rhizosphere soils of GM and non-GM (IM) rice were analyzed for soil chemistry, population densities of soil microorganisms, and microbial community structure (using pyrosequencing technology) at three growth stages (seedling, tillering, and maturity). There was no significant difference in the soil chemistry between GM and non-GM rice. The microbial densities of the GM soils were found to be within the range of those of the non-GM rice. In the pyrosequencing analyses, Proteobacteria and Chloroflexi were dominant at the seedling stage, while Chloroflexi showed dominance over Proteobacteria at the maturity stage in both the GM and non-GM soils. An UPGMA dendrogram showed that the soil microbial communities were clustered by growth stage. Taken together, the results from this study suggest that the effects of MSRB2-Bar-8 cultivation on soil microorganisms are not significant.

• KSBB Journal
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• 제29권2호
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• pp.81-86
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• 2014

Lactobacilli, the dominant species of microorganisms in the vaginal flora of healthy women, play important roles to prevent bacterial vaginosis and other sexually transmitted diseases. In this study, we carried out studies on stress adaptation prior to various stress treatment. We found that heat or salt adapted KLB46 showed higher cell viability than non adapted upon heat stress at $60^{\circ}C$ for 20 min. When chloramphenicol was added during the adaptation process, heat tolerance was abolished. This result suggested that de novo protein synthesis was essential during adaptation.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1533-1541
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• 2016

Samples of doenjang (a fermented soybean paste) were prepared with different types of salts; purified salt (PS), 3-year-aged solar salt (SS3), 1-year-aged solar salt (SS1), and bamboo salt (BS, 3^rd processing product). For starter doenjang samples, selected starters comprising two bacilli, one yeast, and one fungus were inoculated, whereas for non-starter doenjang samples, microorganisms present in rice straw were inoculated after enrichment. The doenjang samples were fermented for 13 weeks at 25℃. During the fermentation period, SS and BS doenjang samples showed higher bacilli counts as well as much lower yeast counts than PS doenjang. At 13 weeks, yeast counts of starter doenjang samples were 7.75, 5.69, 6.08, and 4.74 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. For non-starter doenjang samples, counts were 7.17, 5.05, 5.92, and 4.54 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. SS and BS promoted growth of bacilli but inhibited growth of yeasts compared with PS. Debaryomyces hansenii was the dominant yeast in PS doenjang, whereas Candida guilliermondii and Pichia sorbitophila were dominant in SS and BS doenjang. In the sensory evaluation, SS and BS doenjang scored better than PS doenjang. In conclusion, SS and BS seem better than PS for production of high-quality doenjang.

• 한국축산식품학회지
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• 제39권5호
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• pp.804-819
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• 2019

Ezine cheese is a non-starter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin status. Non-starter lactic acid bacteria (NSLAB) have a substantial effect on the quality and final sensorial characteristics of long-ripened cheeses. The dominance of NSLAB can be attributed to their high tolerance to the hostile environment in cheese during ripening relative to many other microbial groups and to its ability to inhibit undesired microorganisms. These qualities promote the microbiological stability of long-ripened cheeses. In this study, 144 samples were collected from three dairies during the ripening period of Ezine cheese. Physicochemical composition and NSLAB identification analyses were performed using both conventional and molecular methods. According to the results of a 16S rRNA gene sequence analysis, 13 different species belonging to seven genera were identified. Enterococcus faecium (38.42%) and E. faecalis (18.94%) were dominant species during the cheese manufacturing process, surviving 12 months of ripening together with Lactobacillus paracasei (13.68%) and Lb. plantarum (11.05%). The results indicate that NSLAB contributes to the microbiological stability of Ezine cheese over 12 months of ripening. The isolation of NSLAB with antimicrobial activity, potential bacteriocin producers, yielded defined collections of natural NSLAB isolates from Ezine cheese that can be used to generate specific starter cultures for the production of Ezine cheese (PDO).

• Korean Chemical Engineering Research
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• 제52권1호
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• pp.92-97
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• 2014

퍼클로레이트($ClO_4^-$)는 지표수는 물론이고 토양지하수의 신규 오염물이다. $ClO_4^-$는 요오드가 갑상선에 흡수되는 것을 방해하므로 갑상선 호르몬 생성을 저하시킨다. $ClO_4^-$는 물에서 매우 용해도가 높고 안정적이라는 특징으로 인해 $ClO_4^-$를 환원하는 세균(PRB)에 의한 생분해가 자연저감의 가장 중요한 요인으로 여겨지고 있다. 산업단지 내 하천은 점 또는 비점오염원으로부터 배출된 $ClO_4^-$에 오염될 잠재성이 있다. 그래서 본 연구에서는 구미지역 산업단지 내 하천에서 물시료를 채취하여 하천미생물의 $ClO_4^-$ 분해 잠재능을 회분배양으로 조사하였다. 외부 전자공여체를 첨가하지 않고 83시간 동안 배양한 결과 모든 시료는 $ClO_4^-$ 제거효율이 0.77% 이하로 매우 낮은 것으로 나타났다. 그러나 외부 전자공여체(acetate, thiosulfate, $S^0$, 또는 $F^0$)를 첨가한 경우는 제거효율이 최고 100%로 나타났고, 첨가된 전자공여체의 종류와 시료채취지점에 따라 제거효율은 다양한 것으로 나타났다. 본 연구에서 사용한 전자공여체 중에서는 acetate를 사용했을 때 $ClO_4^-$분해효율이 가장 우수한 것으로 나타나 종속영양방식 PRB의 활성이 우세함을 알 수 있었다. 본 연구의 결과는 산업단지 내 하천 미생물에 의한 $ClO_4^-$ 자연저감에 대한 기초정보를 제공하여 원위치 생물복원처리에서 $ClO_4^-$ 생분해를 증진하기 위한 전략마련에 유용하게 사용될 것이다.

• 한국환경보건학회지
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• 제47권2호
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• pp.182-191
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• 2021

Objective: This study was performed to detect indicator bacteria in drinking spring water samples in Gwangju City and to identify their genus using the VITEK-II system. Methods: The subjects were ten drinking spring water sites in Gwangju. Samples of spring water were taken every month from September 2019 to August 2020. We analyzed for the indicator bacteria Yersinia and microorganisms isolated from the spring water. Result: According to the research results on indicator bacteria, general bacteria in st1-st7 with sterilization facilities in the spring and summer were investigated in the range of 0-2 CFU/mL and 0-12 CFU/mL. In st9, where a sterilization facility was not installed, the most general bacteria were detected (160 CFU/mL). Total coliform and fecal coliform showed unsatisfied rates of 16.7 and 11.1% in spring and 14.7 and 11.8% in summer, respectively. The unsatisfied rates of total coliform for the designated and non-designated spring water facilities were 3.8 and 47.1%, respectively, and for the fecal coliform group they were 2.5 and 35.3%. The difference was confirmed according to the presence of a sterilization facility. Yersinia spp. was not detected in all drinking spring water. Forty-one strains in 25 species were isolated from ten sites. The results classified as major dominant species are Pseudomonas spp. 14.6%, Pantoea spp. 9.8%, Serratia spp. 9.8%, Acinetobacter spp. 9.8%, Citrobacter spp. 7.3%, Bordetella spp. 7.3%, Delftia spp. 4.9%, and Enterobacter spp. 4.9%. Conclusions: Based on the result that various species derived from fecal pollution and artificial pollutants were detected in the non-specified public spring water facilities that many people use, the facilities need institutional complements such as continuous management or complete shutdowns.

• 한국토양비료학회지
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• 제43권2호
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• pp.180-187
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• 2010

유전자변형 벼 및 비변형 벼 재배시 근권미생물의 특성 및 군집변동상을 조사하였다. 유전자변형 벼 재배 및 비변형 벼 재배 근권토양 및 뿌리표면인 근면의 세균수는 큰 차이가 없었다. 수원지역 2006년도 포장시험에서 근권토양의 세균은 유전자변형 벼의 경우 Afipia가 12.5%, Spingomonas 10.0%, Ramlibacter 10.0%, Mycobacterium 7.5%, Tetrasphaera 7.5%였으며, 유전자비 변형 벼는 Afipia가 7.3%, Spingomonas 12.2%, Ramlibacter 7.3%, Mycobacterium 17.1%, Tetrasphaera 속이 14.6%로 우점하였다. 예산 시험포장에서 재배한 벼 뿌리표면의 우점세균은 2007년도에는 유전자 변형 벼 시험포에서 Arthrobacter 속 12.7% 유전자비 변형 벼 시험포에서는 Burkholderia 속 22.2%였으며, 2008년도에는 유전자변형 벼 시험포에서 Paucimonas 속이 26.6%, 비변형 벼 시험포에서는 Chryseobacterium 속이 15.4 %를 점유하였다. PLFA에 의한 미생물 군집은 유전자변형 벼 재배 유무에 따른 조건에서는 뚜렷한 경향이 없었지만 토양 간에는 다른 특성을 보였다.

• 한국환경농학회지
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• 제32권2호
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• pp.95-101
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• 2013

본 연구는 Protox 제초제내성 벼 재배가 토양 미생물에 미치는 영향과 수평적 유전자 이동성을 알아보기 위해 수행되었다. 생육단계별 토양 미생물 군집밀도의 경우 제초제내성 벼를 재배한 근권 토양 미생물 군집밀도가 비 형질전환 벼의 근권 토양과 유사하여 제초제저항성 벼 재배가 근권 토양 미생물에 미치는 영향은 비슷할 것으로 추정되었다. 근권 토양의 우점 미생물 분포 양상을 분석한 결과, Proteobacteria, Firmicutes와 Actinobacteria 순으로 나타났으며 우점종과 점유율은 거의 유사하였다. 근권 토양 DNA에 대한 DGGE 분석 결과, 제초제내성 벼와 비 형질전환 벼의 근권 토양 미생물 군집의 profile 변화는 나타나지 않았다. 제초제내성 벼 재배에 따른 토양 화학성을 분석한 결과, 비 형질전환 벼의 근권 토양간 화학성은 차이가 없는 것으로 나타났다. 제초제 내성 벼에 도입된 유전자군을 대상으로 근권 토양 DNA에 대한 PCR 분석 결과, 도입 유전자의 잔존성이 길지 않아 수평적 유전자 이동성은 희박할 것으로 추정되었다.

• 한국환경농학회지
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• 제30권4호
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• pp.466-472
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• 2011

본 연구는 국내에서 개발된 형질전환 콩 재배 시 토양 미생물 군집에 미치는 영향과 수평적 유전자 이동 여부를 알아보기 위해 수행되었다. 성숙기 토양의 미생물 군집밀도의 경우 형질전환 콩 근권 토양 미생물 군집밀도가 비 형질전환 콩 근권 토양과 유사하여 형질전환 콩 재배가 근권 토양 미생물에 영향을 미치지 않는 것으로 나타났다. 근권 토양의 우점 미생물 분포 양상 분석 결과, Proteobacteria, Firmicutes와 Actinobacteria 순으로 나타났으며 점유율은 다소 차이를 보였으나 우점종은 거의 유사하였다. 근권 토양 DNA에 대한 DGGE 분석 결과, 형질전환 콩과 비 형질전환 콩의 근권 토양 미생물 군집의 변화는 보이지 않았다. 형질전환 콩 재배에 따른 토양의 화학성을 분석한 결과, 형질전환 콩과 비 형질전환 콩의 근권 미생물상의 명확한 차이가 나타날 정도로 토양간 화학성의 차이는 크지 않았다. 형질전환 작물에 도입된 유전자군을 대상으로 식물체와 근권 토양 DNA에 대한 PCR 분석을 수행한 결과 수평적 유전자 이동성은 일어나지 않은 것으로 추정되었다.