• Journal of Microbiology and Biotechnology
• /
• 제20권11호
• /
• pp.1592-1596
• /
• 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
• /
• 제20권1호
• /
• pp.169-178
• /
• 2010

The microbial community structure in Thailand soils contaminated with low and high levels of arsenic was determined by denaturing gradient gel electrophoresis. Band pattern analysis indicated that the bacterial community was not significantly different in the two soils. Phylogenetic analysis obtained by excising and sequencing six bands indicated that the soils were dominated by Arthrobacter koreensis and $\beta$-Proteobacteria. Two hundred and sixty-two bacterial isolates were obtained from arsenic-contaminated soils. The majority of the As-resistant isolates were Gramnegative bacteria. MIC studies indicated that all of the tested bacteria had greater resistance to arsenate than arsenite. Some strains were capable of growing in medium containing up to 1,500 mg/l arsenite and arsenate. Correlations analysis of resistance patterns of arsenite resistance indicated that the isolated bacteria could be categorized into 13 groups, with a maximum similarity value of 100%. All strains were also evaluated for resistance to eight antibiotics. The antibiotic resistance patterns divided the strains into 100 unique groups, indicating that the strains were very diverse. Isolates from each antibiotic resistance group were characterized in more detail by using the repetitive extragenic palindromic-PCR (rep-PCR) DNA fingerprinting technique with ERIC primers. The PCR products were analyzed by agarose gel electrophoresis. The genetic relatedness of 100 bacterial fingerprints, determined by using the Pearson product-moment similarity coefficient, showed that the isolates could be divided into four clusters, with similarity values ranging from 5-99%. Although many isolates were genetically diverse, others were clonal in nature. Additionally, the arsenic-resistant isolates were examined for the presence of arsenic resistance (ars) genes by using PCR, and 30% of the isolates were found to carry an arsenate reductase encoded by the arsC gene.

• Food Science and Biotechnology
• /
• 제18권4호
• /
• pp.1035-1037
• /
• 2009

In this study we analyzed the dynamic changes in microbiota composition during kochujang fermentation at $30^{\circ}C$. During fermentation, the viable cell counts slowly increased and reached $3.2{\times}10^7$ for aerobic bacteria, $8.3{\times}10^3$ for yeast, and $1.4{\times}10^3$ CFU/mL for fungi after 60 days. Bacilli were found to be the most dominant microorganisms throughout the fermentation process. Using the culture dependent method Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloquefaciens were found to be the main species during the early stages of fermentation; however, Bacillus pumilus and Bacillus stearothermophilus became the most dominant species during the late stage of fermentation. In contrast, when the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method was used Bacillus ehimensis was found to be the dominant species during the early stage of fermentation and Bacillus megaterium, B. pumilus, B. subtilis, and B. licheniformis were dominant in the ate stages. These results indicate various other Bacillus species rather than just B. subtilis and B. licheniformis might be involved in the fermentation of kochujang.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
• /
• pp.133-137
• /
• 2004

Tetrachloroethylene(PCE) dechlorination was investigated in an anaerobic enrichment culture from landfill soil. Anaerobic PCE dechlorinating microorganisms could convert 150mg/L of PCE via trichloroethylene(TCE) to cir-1,2-dichloroethylene(CDCE) within 2 days at the optimum temperature of 30 to 35$^{\circ}C$. The enrichment culture could dechlorinate TCE but did not degrade other chlorinated aliphatic compounds, such as cDCE, trans-1,2-dichloroethylene, 1,1-dichloroethylene, 1,1-dichloroethane, 1,2-dichloro- ethane, and 1,1,1-trichloroethane during 5 days incubation. Several isolates from the enrichment culture did not show dechlorinating activity of PCE. Microbial analysis of the dechlorinating enrichment culture by using Polymerase chain reaction-Denaturing gradient gel electrophoresis (PCR-DGGE) method showed that at least three microorganisms were related to the anaerobic PCE dechlorination in the enrichment

• 한국습지학회지
• /
• 제14권3호
• /
• pp.419-428
• /
• 2012

식물플랑크톤의 동정은 숙련된 전문가에게도 어려운 과제이다. 별 특징없는 외형과 다양한 크기와 종은 형태학적으로 구분하기에 어려움이 있다. 본 연구에서는 미생물 군집의 다양성을 분석하는데 효과적인 fingerprinting 기법인 PCR-DGGE 방법을 사용하여 이런 형태학적 동정의 제한점을 보완하고자 하는데 목적이 있다. 5곳의 호수 샘플로부터 2008년 8월 총 46개의 band를 찾을 수 있었고, 2008년 11월 총 26개 band를 찾을 수 있었다. 이 fingerprint 결과는 각각 다른 샘플링 장소를 비교하는데 용이하였다. 본 연구에서 PCR-DGGE 방법은 북한강 호수들의 플랑크톤 군집의 다양성을 파악하는데 사용되었고, 이 DGGE 기법이 플랑크톤의 동정기법으로써의 가능성을 검토해보았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권4호
• /
• pp.543-549
• /
• 2007

Two experiments were conducted to investigate the effects of disodium fumarate on the in vitro rumen fermentation profiles of different substrates and microbial communities. In experiment 1, nine diets (high-forage diet (forage:concentrate, e.g. F:C = 7:3, DM basis), medium-forage diet (F:C = 5:5, DM basis), low-forage diet(F:C = 1:9, DM basis), cracked corn, cracked wheat, soluble starch, tall elata (Festuca elata), perennial ryegrass and rice straw) were fermented in vitro by rumen microorganisms from local goats. The results showed that during 24 h incubations, for all substrates, disodium fumarate increased (p<0.05) the gas production, and tended to increase (p<0.10) the acetate, propionate and total VFA concentration and decrease the ratio of acetate to propionate, whereas no treatment effect was observed for the lactate concentration. The apparent DM loss for tall elata, perennial ryegrass and rice straw increased (p<0.05) with the addition of disodium fumarate. With the exception of tall elata, perennial ryegrass and rice straw, disodium fumarate addition increased the final pH (p<0.05) for all substrates. In experiment 2, three substrates (a high-forage diet, a medium-forage diet and a high concentrate diet) were fermented by mixed rumen microbes in vitro. A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique was applied to compare microbial DNA fingerprints between substrates at the end of 24 h incubation. The results showed that when Festuca elata was used as substrate, the control and disodium fumarate treatments had similar DGGE profiles, with their similarities higher than 96%. As the ratio of concentrate increased, however, the similarities in DGGE profiles decreased between the control and disodium fumarate treatment. Overall, these results suggest that disodium fumarate is effective in increasing the pH and gas production for the diets differing in forage: concentrate ratio, grain cereals and soluble starch, and in increasing dry matter loss for the forages (tall elata, perennial ryegrass and rice straw) in vitro, whereas its effect on changes of ruminal microbial community may largely depend on the general nature of the substrate.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권7호
• /
• pp.957-966
• /
• 2017

Objective: To understand the dynamic structure, function, and influence on nutrient metabolism in hosts, it was crucial to assess the genetic potential of gut microbial community in yaks of different ages. Methods: The denaturing gradient gel electrophoresis (DGGE) profiles and Illumina-based metagenomic sequencing on colon contents of 15 semi-domestic yaks were investigated. Unweighted pairwise grouping method with mathematical averages (UPGMA) clustering and principal component analysis (PCA) were used to analyze the DGGE fingerprint. The Illumina sequences were assembled, predicted to genes and functionally annotated, and then classified by querying protein sequences of the genes against the Kyoto encyclopedia of genes and genomes (KEGG) database. Results: Metagenomic sequencing showed that more than 85% of ribosomal RNA (rRNA) gene sequences belonged to the phylum Firmicutes and Bacteroidetes, indicating that the family Ruminococcaceae (46.5%), Rikenellaceae (11.3%), Lachnospiraceae (10.0%), and Bacteroidaceae (6.3%) were dominant gut microbes. Over 50% of non-rRNA gene sequences represented the metabolic pathways of amino acids (14.4%), proteins (12.3%), sugars (11.9%), nucleotides (6.8%), lipids (1.7%), xenobiotics (1.4%), coenzymes, and vitamins (3.6%). Gene functional classification showed that most of enzyme-coding genes were related to cellulose digestion and amino acids metabolic pathways. Conclusion: Yaks' age had a substantial effect on gut microbial composition. Comparative metagenomics of gut microbiota in 0.5-, 1.5-, and 2.5-year-old yaks revealed that the abundance of the class Clostridia, Bacteroidia, and Lentisphaeria, as well as the phylum Firmicutes, Bacteroidetes, Lentisphaerae, Tenericutes, and Cyanobacteria, varied more greatly during yaks' growth, especially in young animals (0.5 and 1.5 years old). Gut microbes, including Bacteroides, Clostridium, and Lentisphaeria, make a contribution to the energy metabolism and synthesis of amino acid, which are essential to the normal growth of yaks.

• 대한환경공학회지
• /
• 제30권10호
• /
• pp.1021-1027
• /
• 2008

본 연구에서는 비점오염물질을 처리하기 위해 생물막 공정이 도입되었다. 반응기내의 생물막의 성장으로 위해 세라믹 담체가 사용되었으며, 담체의 충전률은 각각 5% 및 15(v/v)%였다. 이후, 반응기는 각각 0, 5, 10, 15일의 무강우기간에 따라 회분식으로 운전되었다. COD 및 NH$_4{^+}$-N의 제거효율이 담체 충전률, 온도 및 무강우기간에 따라 조사되었으며, 추가적으로 polymerase chain reaction (PCR)-denaturing gel gradient electrophoresis(DGGE)와 INT-dehydrogenase activity(DHA) test를 통하여 미생물 군집 및 활성도가 해석되었다. 운전 결과, 무강우기간이 늘어남에도 충전률에 관계없이 COD의 제거는 안정적으로 일어났다. COD는 25$^{\circ}C$에서는 6$\sim$8 hr, 10$^{\circ}C$에서는 약 15 hr의 반응시간이 필요하였다. DGGE 분석 결과, 무강우기간이 늘어남에 따라 식종 슬러지에서 발견되는 미생물에서 저니토에서 주로 발견되는 미생물로 변화됨을 확인할 수 있었다. 또한 INT-DHA법에 의한 미생물의 활성도 측정 결과, 15일의 무강우기간에도 활성도의 감소는 관찰되지 않았다.

• Journal of Microbiology and Biotechnology
• /
• 제24권8호
• /
• pp.1026-1033
• /
• 2014

The fecal microbiotas were investigated in 13 healthy Thai subjects using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Among the 186 DNA bands detected on the polyacrylamide gel, 37 bands were identified as representing 11 species: Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides uniformis, Bacteroides vulgatus, Clostridium colicanis, Eubacterium eligenes, E. rectale, Faecalibacterium prausnitzii, Megamonas funiformis, Prevotella copri, and Roseburia intestinalis, belonging mainly to the groups of Bacteroides, Prevotella, Clostridium, and F. prausnitzii. A dendrogram of the PCR-DGGE divided the subjects; vegetarians and non-vegetarians. The fecal microbiotas were also analyzed using a quantitative real-time PCR focused on Bacteroides, Bifidobacterium, Enterobacteriaceae, Clostrium coccoides-Eubacterium rectale, C. leptum, Lactobacillus, and Prevotella. The nonvegetarian and vegetarian subjects were found to have significant differences in the high abundance of the Bacteroides and Prevotella genera, respectively. No significant differences were found in the counts of Bifidabacterium, Enterobacteriaceae, C. coccoides-E. rectale group, C. leptum group, and Lactobacillus. Therefore, these findings on the microbiota of healthy Thais consuming different diets could provide helpful data for predicting the health of South East Asians with similar diets.

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