• 한국미생물·생명공학회지
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• 제35권2호
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• pp.150-157
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• 2007

디젤 오염 토양 정화를 위해 식물과 미생물의 상호관계를 활용하는 생물복원에 관한 연구를 수행하였다. 디젤을 분해하는 근권 세균인 Rhodococcus sp. 412와 디젤에 내성을 가지고 있는 식물인 옥수수(Zea mays)를 이용하여 디젤로 오염되어진 토양의 디젤 제거능과 미생물 군집변화를 조사하였다. 실험 개시 30일 후, 디젤 오염 토양에서 Rhodococcus sp. 412를 접종한 토양의 옥수수의 성장이 412균주를 접종하지 않은 토양에서의 옥수수 성장보다 약간 우수하였다. 또한 식물을 식재하거나 412균주를 접종한 토양에서 존재하는 토양에서 디젤의 잔류농도도 낮게 나타났다. 이러한 결과를 디젤 오염 토양 정화를 위해 옥수수와 Rhodococcus sp. 412를 동시에 활용하는 것이 유리함을 의미한다. 토양세균 군집 변화를 16S rDNA-PCR과 DGGE(denaturing gradient gel electrophoresis) fingerprinting 방법을 이용하여 분석하였다. 비오염 토양 시료와 디젤 오염토양 시료의 DGGE fingerprint의 유사도는 $20.8{\sim}39.3%$이었다. 또한, 비오염 토양 시료 사이의 DGGE fingerprint의 유사도는 $21.9{\sim}53.6%$, 그리고 디젤 오염 토양 시료 사이의 유사도는 $31.6{\sim}50.0%$이었다. 이러한 결과는 디젤 오염으로 인해 토양 세균 군집구조가 영향을 받았음을 시사한다.

• 한국유기농업학회:학술대회논문집
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• 한국유기농학회 2009년도 하반기 학술대회
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• pp.302-302
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• 2009

유기농업에서 유기물은 양분의 공급, 토양의 이화학성 개선, 토양의 생물학적 건전성 유지 등 중요한 역할을 한다. 토양의 생물학적 건전성은 토양의 생태계적 기능을 지속적으로 유지시키는 토양미생물이 관여하고 있다. 따라서 본 연구는 유기물의 장기연용에 따른 밭토양 미생물의 다양성을 비교 분석하였다. 여러 가지 유기자원을 동일한 기준으로 매년 동일 장소에 처리하였다. 사용된 유기자원은 가축분퇴비, 채종유박인 유기질비료, 볏짚으로만 퇴비화한 볏짚퇴비와 겨울철 휴한기에 헤어리베치를 재배하여 이듬해 봄에 예취한 후 토양에 환원한 녹비처리구, NPK구, 가축분퇴비를 혼용처리한 NPK퇴비군, 양분을 전혀 시용하지 않은 무비구 등 총 7처리구였다. 각각의 처리구에서 토양(0-20 cm)을 채취하여 배양성 토양미생물은 희석평판법으로 해당 선백배지에 시료를 도말 하여 조사하였고 비배양성 미생물은 토양으로부터 genomic DNA를 추출하여 세균의 16S rDNA를 증폭시킨 후 denaturing gradient gel electrophoresis (DGGE)를 수행하여 분석하였다. 주요결과를 요약하면 밭토양에 서식하는 토양미생물의 균수는 처리별간의 차이를 보였으며 유기물처리구가 화학비료처리구보다 높았다. DGGE 분석을 통해 유기물 처리에 따른 군집의 다양성을 살펴본 결과 Fig. 1에서 보는바와 같이 Gel 상에서 다양한 위치의 밴드를 확인할 수 있었고 처리별로 특이 밴드가 있음을 확인할 수 있었다. Fig. 1에서 얻은 DGGE profile상의 밴드 강도와 수를 비교하여 Fig 2와 같은 dendrogram을 나타낼 수 있었다.

• 환경생물
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• 제29권3호
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• pp.225-235
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• 2011

하절기 수화발생이 빈번한 대청호에서 2003~2005년(3년)에 걸쳐 분자생태학적 방법의 하나인 DGGE를 이용하여 시간에 따른 미생물 군집구조의 변화를 연구하였다. 조사기간 동안 출현한 식물플랑크톤을 형태학적으로 분류한 결과 Cyanophyceae가 우점하였고, 이중에서 Microcystis, Planktothrix (Oscillatoria), Phormidium 그리고 Anabaena 속이 크게 우점하였다. 분자적 군집분석 방법으로서 16S rDNA의 DGGE profile 분석과 계통학적 분류에 의하여 우점하는 미생물 군집의 구조와 다양성을 확인하였다. Microcystis는 조사기간 동안 지속적으로 우점하였으나, Planktothrix는 2003년과 2004년 9월에, Anabaena는 2005년 9월, 그리고 Aphanizomenon은 2003년 8월에 우점하였다. DGGE와 계통분류학적 분석방법은 형태학적 분석법에 의해 얻지 못하는 새로운 정보를 제공하며, 남조류와 수생 세균사이의 상관관계를 추정할 수 있고, 그들의 유전적 다양성을 보다 자세하게 확인할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.376-383
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• 2005

Alcaligenes sp. JMP228 carrying 2,4­dichlorophenoxyacetic acid (2,4-D) degradative plasmid pJP4 was inoculated into natural soil, and transfer of the plasmid pJP4 to indigenous soil bacteria was investigated with and without 2,4-D amendment. Plasmid pJP4 transfer was enhanced in the soils treated with 2,4-D, compared to the soils not amended with 2,4-D. Several different transconjugants were isolated from the soils treated with 2,4-D, while no indigenous transconjugants were obtained from the unamended soils. Inoculation of the soils with both the donor Alcaligenes sp. JMP228/pJP4 and a recipient Burkholderia cepacia DBO 1 produced less diverse transconjugants than the soils inoculated with the donor alone. Repetitive extragenic palindromic-polymerase chain reaction (REP-PCR) analysis of the transconjugants exhibited seven distinct genomic DNA fingerprints. Analysis of 16S rDNA sequences indicated that the transconjugants were related to members of the genera Burkholderia and Pandoraea. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that inoculation of the donor caused clear changes in the bacterial community structure of the 2,4-D­amended soils. The new 16S rRNA gene bands in the DGGE profile corresponded with the 16S rRNA genes of 2,4-D­degrading transconjugants isolated from the soil. The results indicate that introduction of the 2,4-D degradative plasmid as Alcaligenes sp. JMP228/pJP4 has a substantial impact on the bacterial community structure in the 2,4-D-amended soil.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.118-118
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• 2008

The phylogenetic diversity of microbial communities in calcareous mats from Spearfish Creek, a freshwater stream located in the Black Hills of South Dakota, was examined using PCR-based 16S rDNA sequence analysis. In this study, two types of calcareous mats were compared: mature mats formed on the natural substrate of rock surfaces and developing mats on an artificial substrate of glass slides. Among 63 unique isolates from a clone library of 16S rRNA genes from mature mat samples, there were 8 phyla of Bacteria represented. The predominant phylum was Proteobacteria (48%), with the $\beta$ subclass being the largest group. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes from slide samples collected at intervals for four months showed considerable diversity of the microbial community from the earliest stages of community development. Amplicons isolated from DGGE gels and sequenced indicated that community succession has occurred without increasing microbial diversity. However, light microscopic analysis revealed a significant increase in microbial cell density throughout the community development. Scanning electron microscopy of mat samples provides evidence that diatoms are also important members of calcareous mat communities.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1330-1335
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• 2012

Foot and mouth disease (FMD) is one of the acute infectious diseases in hoofed and even-toed mammals, including pigs, and it occurs via acute infection by Aphthovirus. When FMD is suspected, animals around the location of origin are typically slaughtered and buried. Other methods such as rendering, composting, and incineration have not been verified in practice in Korea. After the FMD incident, the regular monitoring of the microbial community is required, as microorganisms greatly modify the characteristics of the ecosystem in which they live. This is the result of their metabolic activities causing chemical changes to take place in the surrounding environment. In this study, we investigated changes in the microbial community during a 24 week period with DNA extracts from leachate, formed by the decomposition of buried pigs at a laboratory test site, using denaturing gradient gel electrophoresis (DGGE) with a genomic DNA. Our results revealed that Bacteroides coprosuis, which is common in pig excreta, and Sporanaerobacter acetigenes, which is a sulfur-reduced microbe, were continuously observed. During the early stages (0~2 weeks) of tissue decomposition, Clostridium cochlearium, Fusobacterium ulcerans, and Fusobacterium sp., which are involved in skin decomposition, were also observed. In addition, various microbes such as Turicibacter sanguinis, Clostridium haemolyticum, Bacteroides propionicifaciens, and Comamonas sp. were seen during the later stages (16~24 weeks). In particular, the number of existing microbial species gradually increased during the early stages, including the exponential phase, decreased during the middle stages, and then increased again during the later stages. Therefore, these results indicate that the decomposition of pigs continues for a long period of time and leachate is created continuously during this process. It is known that leachate can easily flow into the neighboring environment, so a long-term management plan is needed in burial locations for FMD-infected animals.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.739-749
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• 2013

The seasonal and spatial diversity of picocyanobacteria (Pcy) in lakes of the Great Mazurian Lakes (GLM) system was examined by DGGE analysis of molecular markers derived from the 16S-23S internal transcribed spacer (ITS) of the ribosomal operon and the phycocyanin operon (cpcBA-IGS). The study of nine lakes, ranging from mesotrophy to hypereutrophy, demonstrated seasonal variance of Pcy. The richness and Shannon diversity index calculated on the basis of both markers were higher in spring and lower in early and late summer. No statistically significant relationships were found between the markers and trophic status of the studied lakes or Pcy abundance. There were, however, statistically significant relationships between the diversity indices and sampling time. The analysis pointed to a different distribution of the two markers. The ITS marker exhibited more unique sequences in time and space, whereas a greater role for common and ubiquitous sequences was indicated by the cpcBA-IGS data. Examination of the Pcy community structure demonstrated that communities were grouped in highly similar clusters according to sampling season/time rather than to the trophic status of the lake. Our results suggest that time is more important than trophic status in shaping the diversity and structure of Pcy communities. The seasonal changes in picocyanobacteria and differences in diversity and community structures are discussed in the context of well-established ecological hypotheses: the PEG model, intermediate disturbance hypothesis (IDH), and horizontal gene transfer (HGT).

• 유기물자원화
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• 제13권2호
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• pp.85-90
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• 2005

산불로 훼손된 토양 미생물군집의 생화학적, 유전적 다양성을 비교하기 위하여 2000년에 산불이 일어났던 강릉지역에서 자연복원지 토양(NS), 인공복원지 토양(AS), 정상토양(NS)을 표토층과 심토층에서 채집하였다. 생화학적 다양성 분석을 위해 각 시료를 BIOLOG system에 직접 적용하였으며 통계처리(SPSS)를 통해 군집분석을 수행하였다. 또한 군집의 유전적 다양성은 토양 미생물의 16S-rDNA를 증폭하여 DGGE(Denaturing Gradient Gel Electrophoresis)를 이용하여 분석하였다. 자연복원지의 심토와 표토, 정상토양의 표토에서만 70% 이상의 생화학적 다양성이 나타났으나, 유전적 다양성의 경우 모든 시료에서 53%에서 68%의 범위의 상동성을 나타냈다. 이러한 결과는 토양미생물 군집의 생화학적 다양성이 반드시 유전적 다양성을 반영하지 않는다는 것을 보여준다.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.853-857
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• 2007

The semi-outdoor cultivation of Spirulina platens is was attempted using an underground-water-based medium. Occurrence of contaminant organisms such as Chlorella sp. and Chlamydomonas sp. was not found from a microscopic observation and bacteria were not detected from denaturing gradient gel electrophoresis(DGGE) analysis of PCR-amplified 16S rDNA during the cultivation, owing to pH control and the high quality of the underground water. The mean productivity was high at $10.5g/m^2/d$ with a range of $4.2-12.3g/m^2/d$ despite the unfavorable weather conditions of the rainy season. The cultivated S. platens is included a normal protein content of 58.9%. Consequently, the underground water improved the biomass productivity and the biomass quality because of an abundant supplementation of natural minerals and through a contaminant-free culture.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.704-715
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• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.