• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.633-644
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• 2019

An advanced anaerobic expanded granular sludge bed (AnaEG) and an internal circulation (IC) reactor, which were adopted to treat starch processing wastewater (SPW) and ethanol processing wastewater (EPW), were comprehensively analyzed to determine the key factors that affected the granules and microbial communities in the bioreactors. The granule size of $900{\mu}m$ in the AnaEG reactor was smaller than that in the IC reactor, and the internal and external morphological structures of the granular sludge were also significantly different between the two types of reactors. The biodiversity, which was higher in the AnaEG reactor, was mainly affected by reactor type. However, the specific microbial community structure was determined by the type of wastewater. Furthermore, the dominant methanogens of EPW were mainly Methanosaeta and Methanobacterium, but only Methanosaeta was a major constituent in SPW. Compared with the IC reactor, characteristics common to the AnaEG reactor were smaller granules, higher biodiversity and larger proportion of unknown species. The comparison of characteristics between these two reactors not only aids in understanding the novel AnaEG reactor type, but also elucidates the effects of reactor type and wastewater type on the microbial community and sludge structure. This information would be helpful in the application of the novel AnaEG reactor.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.382-388
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• 2002

In order to assess the effects of organic fertilizer on soil microbial community structure and diversity in the greenhouse fields, fatty acid methyl ester (FAME) was analyzed by the MIDI (Microbial ID, Inc., Newark, DE, U.S.A.) system and enumerations were performed. In relation to bacterial division of each sample, low GC Gram-positive bacteria were predominant among bacteria cultured on aerobic bacteria media. On the other hand, alpha subdivision was predominant on proteobacteria of control and OM (organic matter) 1 treated plot, and Flavobacterium spp. existed in OM2 plot on crystal violet media of all samples. Shannon-weaver Index (H) of OM1 plot varied most by 1.9 and 5.0 among bacteria cultured on aerobic bacteria media and crystal violet media, respectively. Our results revealed that addition of the organic wastes to soil led to a highly diverse microbial community, but the excessive amounts of organic and mineral fertilizer applied in the greenhouse fields produced excess nutrients in soil and led to simplification on bacterial populations.

• 한국토양비료학회지
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• 제45권3호
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• pp.377-384
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• 2012

온도조건이 유기물의 질소무기화율, 인지질 지방산유래 미생물 분포와 군집구조에 미치는 영향을 평가하고자 수행하였다. 비화산회토양 30 g에 입상유기질비료, 음식물퇴비, 돈분퇴비를 각각 2 g씩 잘 혼합한 후 $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$에서 항온배양을 하면서 질소 무기화량과 인지질 지방산 함량을 분석하였다. 질소 무기화율은 온도와 비례하여 증가하였으며 음식물퇴비>입상유기질비료>돈분퇴비 순으로 질소무기화율이 높았다. 지방산 유래 미생물 그룹의 분포는 온도, 유기물종류에 따라 차이를 보였으며 시간이 경과 할수록 미생물의 밀도는 감소하는 경향을 나타냈다. G-/G+, F/B, Unsat/sat비는 온도가 올라가면서 감소하였다. 인지질 지방산 함량을 이용하여 주성분 분석을 한 결과 270일에 온도에 따라 입상유기질비료는 뚜렷한 미생물군집구조를 보였다. 결론적으로 미생물 활성은 온도, 유기물 종류에 따라 상대적인 민감도와 시기별로 차이를 보였다.

• 한국환경농학회지
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• 제27권2호
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• pp.133-138
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• 2008

Fire can affect microbial community structure of soil through altered environmental conditions, nutrient availability, and biotic source for microbial re-colonization. We examined the influence of fire on chemical properties and soil enzyme activities of soil for 10 months. We also characterized the soil microbial community structure through ester-linked fatty acid analysis(EL-FAME). For this study, we established five burned plots(1*1 m) and 5 unburned plots outside the margin of fire. Soil was sampled three soil cores in a each plots and composited for analysis at 1, 3, 5, 8, and 10 month after fire. The fire caused an increase in soil pH, exchangeable Ca, and Mg, organic matter, available $P_2O_5$ compared to unburned sites. The content of $NH_4-N$ in burned site was significantly higher than that of unburned site and this effect continued for 8 months after fire. There was no difference of $NO_3-N$ content in soil between burned and unburned site. Fire caused no change in acid phosphatase and arylsulfatase activities but $\beta$-glucosidase and alkaline phosphatase activities in burned site were increased compared to unburned site. Microbial biomass as estimated by total concentration of EL-FAMEs in burned sites was significantly higher than that of unburned sites at one month after fire. Burned site decreased the EL-FAMEs indicative of gram-positive bacteria and tended to increase the fatty acid associated with gram-negative bacteria at one and three months after fire. The sum of EL-FAME compound $18:2{\omega}6,9c$ and $18:1{\omega}9c$ as served fungal biomarkers was decreased in burned site compared to unburned site.

• Journal of Ecology and Environment
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• 제36권4호
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• pp.223-233
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• 2013

Acid deposition is one of the most serious environmental problems in ecosystems. The present study surveyed the effects of simulated acid rain on leaf litter mass loss and microbial community in the decomposing leaf litter of Sorbus anifolia in a microcosm at $23^{\circ}C$ and 40% humidity. Microbial biomass was measured by substrate-induced respiration (SIR) and phospholipid fatty acids (PLFAs), and the microbial community structures were determined by composition of PLFAs at each interval of decomposition in litter sample and at each pH treatment. The microbial biomass showed peaks at mid-stage of decomposition, decreasing at the late stage. The leaf litter mass loss of S. anifolia decreased with decreasing pH during early and mid-decomposition stages; however the mass loss becomes similar between pH treatments at late-decomposition stage. The acidification remarkably lowers the microbial biomass of bacteria and fungi; however, microbial diversity was unchanged between pH treatments at each stage of litter decomposition. With changes of decomposition stage and pH treatment there were considerable differences in replacement and compensation of microbial species. Fungi/bacteria ratio was considerably changed by pH treatment. The PLFA profile showed significantly larger fungi/bacteria ratio at pH 5 than pH 3 at the early stage of decomposition, and the difference becomes smaller at the later decomposition stage. At low pH, pH 3 and pH 4, the fungi/bacteria ratios were stable according to the litter decomposition stages. Simulated acid rain caused decreases of 10Me17:0, 16:1${\omega}$7c, 18:1${\omega}$7, 15:0, but increase of 24:0. In addition, litter mass loss showed significant positive correlation with microbial biomass measured by SIR and PLFA on the decomposing leaf litter.

• 한국토양비료학회지
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• 제43권2호
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• pp.194-199
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• 2010

퇴비 등의 유기물 시용은 화학적, 생물적 토양 특성을 변화시킬 수 있으나 그 성분함량과 시용량에 따라 다를 수 있다. 고추 주산지인 경북 영양의 미사질 양토에서 퇴비 0, 30, 60 Mg $ha^{-1}$를 시용하였을 때 토양의 미생물상의 변화를 인지질지방산 분석을 통해 분석하였다. 퇴비 시용량 30과 60 Mg $ha^{-1}$ 을 무처리와 각각 비교하였을 때 세균, 사상균, 균근균 지표지방산의 양은 유의성있는 증가를 보였으며 사상균/세균의 지방산 비와 불포화/포화지방산의 비도 각각 증가하였다. 그러나, 퇴비 시용량의 증가는 그람$^-$/그람$^+$ 세균 지방산의 비는 증가시켰으나 불포화/포화지방산의 비는 감소시켰다. 퇴비는 토양의 화학성과 미생물 군락을 부분적으로 증가시킬 수 있으나, 퇴비량의 증가는 미생물 군락의 구조만을 변화시킬 수 있었다.

• 한국물환경학회지
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• 제24권2호
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• pp.195-200
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• 2008

To analyze the riverine microbial community structure, genetic fingerprints and ecological indexes such as species abundances, diversity, evenness, dominance of targeted rivers in Gyeonggi Province were acquired and evaluated using terminal restriction fragment length polymorphism (T-RFLP) technique. Genetic fingerprinting technique such as T-RFLP, which is able to show the microbial community clearly unlike traditional culture-dependent techniques, was thought to be useful to analyse the riverine microbial ecosystem under various factors. Riverine ecosystem evaluation using visible organisms would give biased results with time, targeted organism and researcher. But, T-RFLP, which can exclude the subjected biases such as culture condition and identification, would be an option to understand natural ecosystem by including the microorganisms that defy culture but perform important functions.

• Korean Chemical Engineering Research
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• 제48권2호
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• pp.147-156
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• 2010

폐가스 처리용 바이오필터의 핵심 요소 기술은 생촉매(미생물), 담체, 설계 운전 기술 및 진단 관리 기술이다. 특히, 바이오필터의 성능은 부하 조건과 바이오필터 내 미생물 군집 구조에 의해 영향을 받는다. 지금까지 바이오필터의 미생물 연구는 대부분 배양법을 기초로 하여 수행되어 왔으나, 최근에 보다 신속하고 정확하게 미생물 군집을 분석할 수 있는 방법들이 제시되고 있다. 본 논문에서는 생리적, 생화학적 및 분자생물학적 미생물 군집 분석 방법과 이를 활용한 바이오필터의 미생물 군집 특성을 조사한 연구사례를 소개하고, 미생물 군집 분석법의 바이오필터에 적용 가능성에 대해 고찰하였다. Community-level physiological profile 방법은 시료 중에 포함된 종속영양미생물의 탄소기질 이용능력을 기반으로 군집 특성을 조사하는 것이며, Phospholipid fatty acid analysis는 미생물 세포막 지방산을 분석하여 군집 특성을 조사하는 방법이다. 환경시료로부터 직접 추출한 DNA를 활용하는 분자생물학적 분석법에는 "partial community DNA analysis"와 "whole community DNA analysis"가 있다. 전자의 방법은 PCR 과정에 의해 증폭시킨 염기서열을 분석하는 것으로 ribosomal operon 유전자가 가장 많이 활용되었다. 이 방법은 다시 PCR fragment cloning 및 genetic fingerprinting으로 구분되며, genetic fingerprinting 방법으로는 denaturing gradient gel electrophoresis, terminal-restriction fragment length polymorphism, ribosomal intergenic spacer analysis 및 random amplified polymorphic DNA 방법으로 세분화된다. 추출된 전체 군집의 DNA를 분석하는 방법에는 total genomic cross-DNA hybridization, 총 추출 DNA의 열 변성/재결합 방법 및 밀도구배를 이용하여 추출한 DNA를 분획화하는 방법 등이 있다.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• 한국환경농학회지
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• 제30권4호
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• pp.367-376
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• 2011

논 토양의 미생물 생태 다양성을 조사하기 위한 효과적인 방법으로 qRT-PCR을 적용하고자 본 연구를 수행하였다. 논 토양 미생물의 gDNA를 분리하기 위하여 Mo Bio kit를 사용한 효과적이고 안정적인 gDNA 분리 방법을 확립하였다. 논 토양 미생물 다양성을 qRT-PCR로 검출하기 위하여 bacteria를 세분한 ${\alpha}$-Proteobacteria, ${\beta}$-Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes 다섯 가지 문과 전체 bacteria, 전체 fungi를 구분할 수 있는 특이 primer set을 선정하여 다양한 조건의 시험을 통하여 최종 조건을 확립하였으며 재현성 실험을 통하여 방법의 유의성을 검증하였다.