• 상하수도학회지
• /
• 제20권3호
• /
• pp.461-467
• /
• 2006

The seasonal change in attached algae and microbial community structure at sedimentation basin of water treatment plant was investigated by using quinone profiles and denaturing gel gradient electrophoresis (DGGE). The photosynthetic bacteria and algae contains PQ-9 and VK-1 as major quinone are major component of the total quinone fraction in attached algae and microorganisms on sedimentation basin trough. The microorganisms containing menaquinones appear to be sensitivity to the change in temperature than those containing ubiquinones. The plot of the mole fraction of dominant quinone species ($f_d$) to the DQ values showed higher sensitivity to the seasonal change in the microbial community structure. The results indicated that quinone and DGGE are useful tool for the evaluation of the changes in the microbial community structure.

• 한국환경과학회지
• /
• 제14권4호
• /
• pp.367-371
• /
• 2005

Soil samples were collected from new-developed wetland soil ecosystem of Tamarix chinesis plantation in Chinese Yellow River Delta in different months of 2003. Soil characteristics, temporal change and spatial distribution of microbial community composition and their relationship with nitrogen turnover and circling were investigated in order to analyze and characterize the role of microbial diversity and functioning in the specific soil ecosystem. The result showed that the total population of microbial community in the studied soil was considerably low, compared with common natural ecosystem. The amount of microorganism followed as the order: bacteria> actinomycetes>fungi. Amount of actinomycetes were higher by far than that of fungi. Microbial population remarkably varied in different months. Microbial population of three species in top horizon was corrected to that in deep horizon. Obvious rhizosphere effect was observed and microbial population was significantly higher in rhizosphere than other soils due to vegetation growth, root exudation, and cumulative dead fine roots. Our results demonstrate that microbial diversity is low, while is dominated by specific community in the wetland ecosystem of Tamarix chinesi.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제28권5호
• /
• pp.12-24
• /
• 2023

The Songji lagoon is brackish environment with a mixture of saline and fresh water, and the interaction of groundwater-lagoon water creates a physicochemical gradient. Although some studies have been conducted on the hydrological and geochemical characteristics of the Songji lagoon, microbial ecological studies have not yet been conducted. In this study, we investigated the effect of groundwater and surface water interaction on water quality as well as microbial community changes in the Songji Lagoon using 16S rRNA gene sequencing. Hydrochemical analyses show that samples were classified as 5 hydrochemical facies (HF) and hydrochemical facies evolution (HFE) revealed the intrusion phase was more dominant (57.9%) than the freshening phase (42.1%). Higher microbial diversity was found in freshwater in comparison to saline water samples. The microbial community at the phylum level shows the most dominance of Proteobacteria with an average of 37.3%, followed by Bacteroidota, Actinobacteria, and Patescibacteria. Heat map analyses of the top 18 genera showed that samples were clustered into 5 groups based on type, and Pseudoalteromonas could be used potential indicator for seawater intrusion.

• 한국의류학회지
• /
• 제35권4호
• /
• pp.431-441
• /
• 2011

Microbial colorants produced from Zooshikella sp. were developed as a reddish dye for fabrics. The reddish colorants were extracted from cell mass of Zooshikella sp. using 100% ethanol and were identified as prodiginine by 1H-NMR and FT-IR analysis. Microbial prodiginine had a maximum spectrophotomatric absorbance at 530nm and were chemically stable and 30 to $60^{\circ}C$. The microbial prodiginine could dye natural fibers such as cotton, silk, and wool as well as synthetic fibers such as nylon. The maximum K/S values of the dyed fiber were shown at 540 run with a color appearance of RP (reddish purple). Silk and nylon had an excellent dyeability among the experimental fibers. The optimum pH for the dyeing of experimental fibers was at pH 3.0 and dyeability was improved as the temperature increased. The cover change of dyed multifiber fabrics with the microbial prodiginine were measured after washing with detergents and a dry cleaning solvent for the selection of a proper fabric against microbial prodiginine. Among the experimental fibers, silk and nylon did not show significant color change after washing. Therefore, under the criteria of dyeability, silk and nylon were excellent fabrics for being dyed by microbial prodiginine.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제27권spc호
• /
• pp.51-63
• /
• 2022

In this study, the TPH(Total Petroleum Hydrocarbon) contamination and microbial ecological characteristics in petroleum-contaminated site were investigated through the correlation among the vertical TPH contamination distribution of the site, the geochemical characteristics, and the indigenous microbial ecology. The high TPH concentration showed in the vicinity of 3~4 m or less which is thought to be affected by vertical movement due to the impervious clay layer. In addition, the TPH concentration was found to have a positive correlation with Fe²⁺, TOC concentration, and the number of petroleum-degrading bacteria, and a negative correlation with the microbial community diversity. The microbial community according to the vertical distribution of TPH showed that Proteobacteria and Firmicutes at the phylum level were dominant in this study area as a whole, and they competed with each other. In particular, it was confirmed that the difference in the microbial community was different due to the difference in the degree of vertical TPH contamination. In addition, the genera Acidovorax, Leptolinea, Rugoshibacter, and Smithella appeared dominant in the samples in which TPH was detected, which is considered to be the microorganisms involved in the degradation of TPH in this study area. It is expected that this study can be used as an important data to understand the contamination characteristics and biogeochemical and microbial characteristics of these TPH-contaminated sites.

• 대한한의학회지
• /
• 제32권5호
• /
• pp.41-49
• /
• 2011

Objectives: To optimize the preservation method of herbal decoction, we investigated the content of principle components of Pyungwi-san, liquiritin, glycyrrhizin, and hesperidin according to preservation temperature and period. We also investigated the changing patterns of pH and microbial population in Pyungwi-san decoction as a model case. Methods: With samples preserved at different temperatures, the content of liquiritin, glycyrrhizin, and hesperidin was determined using HPLC and microbial population was determined as viable counting method up to 8 times every month. Identification of isolated bacteria was performed by 16S rDNA analysis. Results: The content of liquiritin and glycyrrhizin did not change according to the preservation temperature and period, but that of hesperidin was severely decreased at room temperature. The isolate from the decoction was identified as Bacillus licheniformis by 16S rDNA sequence analysis. Microbial population appeared after 3 months' preservation and reached maximum value at 4 months; at all tested temperatures, the pH showed the lowest value (4.4-4.5) simultaneously. Conclusion: From the results, it seems to be that the microbial growth affects the pH of preserved decoction but not the change of liquiritin and glycyrrhizin content.

• 한국기후변화학회지
• /
• 제5권3호
• /
• pp.249-256
• /
• 2014

Permafrost is frozen soil below $0^{\circ}C$ for two or more years. Surface of permafrost is called as active layer that seasonally thaws during the summer. Although the thawing of permafrost may deepen the active layer and consequently increase the microbial activity, the microbial community structure in this habitat has not yet been well described. In this study, we presented bacterial and archaeal diversity in the active layer soil from Resolute, Canada using pyrosequencing analysis. The soil sample was collected from the surface of the marsh covered with moss and Carex. A total of 7,796 bacterial reads for 40 phyla and 245 archaeal reads for 4 phyla were collected, reflecting the high diversity of bacteria. Predominant bacterial groups were Proteobacteria (37.7%) and Bacteroidetes (30.0%) in this study. Major groups in Archaea were Euryarchaeota (51.4%) and Thaumarchaeota (46.1%). Both methane producing archaea and consuming bacteria were detected in this study. Although it might be difficult to characterize microbial community with only one sample, it could be used for the basis of assessing the relative importance of the specific groups with a high resolution on the bacterial and archaeal community in this habitat.

• 한국유기농업학회지
• /
• 제10권1호
• /
• pp.87-97
• /
• 2002

本 試驗은 정해지역의 慣行栽培 土壤과 부산지역의 신개간지 土壤에 微生物 발효퇴비를 각각 90kg/10a, 180kg/10a, 270kg/10a을 施用하여 土壤 微生物相 變化와 알타리 무의 生育, 收量 및 體內咸分에 미치는 影響을 究明하고자 試驗한 結果는 다음과 같다. 1. 栽培地域을 달리하여 미생물상를 調査하였던 바 신개간지 土壤에서 微生物數가 많았으며, 處理間 微生物數 變化는 化學肥料 處理區에서는 微生物數가 약간 減少하는 傾向을 보였으나 微生物 발효퇴비 處理區에서는 施用量이 增加할수록 綱菌數 및 放線菌數는 增加한 반면 絲狀菌數는 약간 減少하였다. 2. 栽培地域을 달리하여 알타리무를 栽培한 結果 김해지역의 慣行栽培 土壤에서 栽培한 알타리 무가 生育 및 收量이 높았으며, 微生物 발효비료 施用量에 따른 알타리 무의 生育 및 收量은 微生物 戀靜繼肥 施用量이 增加할수록 높았고, 특히 10a3당 270kg 處理區에서 가장 높았다. 3. 알타리무를 體內咸分을 분석한 結果 栽培地域 및 施用量間 뚜렷한 差異는 나타나지 않았다.

• 대한치과교정학회지
• /
• 제27권2호
• /
• pp.173-180
• /
• 1997

본 연구는 교정환자를 대상으로 chlorhexidine varnish를 치면에 도포했을 때 치태내 균주의 변화양상을 관찰하여 교정치료환자에 있어 치아우식증예방을 위한 chlorhexidine 사용의 효용성을 평가하고자 하는데 그 목적이 있다. 서울대학교 병원 치과진료부 교정과에 내원한 신환 26명을 대상으로 각 13명씩을 실험군과 대조군으로 구분하여 실험군에는 chlorhexidine varnish를 1주일 간격으로 4희 도포하고 대조군에는 같은 방법으로 placebo varnish를 도포하여 처치 전과 처치 4주후, 처치 8주후의 치태내 균주 변화양상을 간접면역형광현미경법으로 분석하였다. 결과는 다음과 같다. 1. Chlorhexidine varnish 처치에 의해 Streptococcus mutans는 처치 8주후 까지 강력히 억제되었다(p<0.01). 2. Streptococcus sanguis는 chlorhexidine varnish처치 4주후에 일시적으로 증가하였다가(p<0.05) 8주후에 원상으로 회복되었다. 3. Streptococcus mitis, Actinomyces viscosus, Actinomyces naeslundii는 chlorhexidine varnish 처치에 의해 별 다른 변화를 나타내지 않았다.

• 펄프종이기술
• /
• 제34권2호
• /
• pp.54-60
• /
• 2002

The Wastewater of toilet paper mill recycling recovered milk carton was used as a raw material for this study. According to the actual mill conditions, hydraulic retention time was adjusted to 12 hours and F/M (Food/Micro-organism) ratio was adjusted to 0.23. Temperature of aeration basin was varied from 2$0^{\circ}C$ to 5$0^{\circ}C$. The change of Micro-organisms and removal efficiency of pollutant were investigated at the varied temperature of basin. Aeration basin using high thermal microbial inoculants showed more removal efficiency of SS, COD than aeration basin using conventional microbial inoculants at high temperature. Floc consolidation of aeration basin using high thermal microbial inoculants added sludge was better than that of sludge from aeration basin using conventional microbial inoculants.