• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.461-467
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• 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.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.367-371
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• 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.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.12-24
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• 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.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.4
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• pp.431-441
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• 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.

• Journal of Soil and Groundwater Environment
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• v.27 no.spc
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• pp.51-63
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• 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.

• The Journal of Korean Medicine
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• v.32 no.5
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• pp.41-49
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• 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.

• Journal of Climate Change Research
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• v.5 no.3
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• pp.249-256
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• 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.

• Korean Journal of Organic Agriculture
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• v.10 no.1
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• pp.87-97
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• 2002

This study was conducted to investigate the effect of microbial fermentation compost on the growth, yields and components of Altari Radish, and the soil physicochemistry property by cultivating area. microbial fermentation compost, 90kg/10a, 180kg/10a, 270kg/10a, chemical fertilizer plot were used. The results were summarized as follows ; Change of soil microbial after application microbial fermentation compost, The number of bacteria and actinomycetes in developed land showed the increased tendency. The application effects of microbial fermentation compost on the growth and yield of Altari radish were increased by excessive application with all kinds of microbial fermentation compost, especially, treatment plot at 270kg/10a was the highest. Change of components in Altari Radish was not different between treatments.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.173-180
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• 1997

The purpose of this study was to evaluate the effectiveness of chlorhexidine varnish treatment in the prevention of dental caries in orthodontic patients by observing microbial change in dental plaque after varnish treatment. The sample consisted of 26 patients who were classified into an experimental group and a control group, 13 patients each. The experimental group was treated with chlorhexidine varnish once a week for 4 weeks. The control group was treated with placebo varnish using the same procedure, The microbial change was analysed by indirect immunofluorescene technique before treatment and 4 weeks, 8 weeks after treatment. The results were as follows. 1. Streptococcus mutans were strongly suppressed until 8 weeks after chlorhexidine varnish treatment(p<0.01). 2 The proportion of Streptococcus sanguis increased temporarily 4 weeks after chlorhexidine varnish treatment(p<0.05), decreased to original level after 8 weeks. 3. Streptococcus mitts, Actinomyces viscosus, Actinomyces naeslundii did not show significant change after chlorhexidine varnish treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.54-60
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• 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.