• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.52-58
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• 2005

In Korea, little attention has been paid to microbial perchloroethylene (PCE) and/or trichloroethylene (TCE) dechlorination activity and identification of microorganisms involved in PCE reductive dechlorination at a PCE-contaminated aquifer. We performed microcosm tests using the groundwater samples from 4 different contaminated sites (i.e. Changwon A, Changwon B, Bucheon and Yangsan) to assess PCE reductive dechlorination activity. We also adapted molecular techniques to screen what types of known reductive dechlorinators are present at the PCE-contaminated aquifers. In the Changwon A and Changwon B active microcosms where potential electron donors such as sodium propionate, sodium lactate, sodium butyrate, and sodium fumarate, were added, ethylene, an end-product of complete reductive dechlorination of PCE, was detected after a period of 90 days of incubation. In the Bucheon and Yangsan active microcosms, cis-1,2-dichloroethylene (c-DCE) was accumulated without the production of vinyl chloride (VC) and ethylene. Molecular techniques were used to evaluate the microbial community structures in the Changwon B and Yangsan aquifer. We found two sequence types that were closely related to a known PCE to ethylene dechlorinator, named uncultured bacterium clone DCE47, in the Changwon B site clone library. However, in the Yangsan site clone library, no sequence type was closely related to known PCE dechlorinators reported. It is plausible that microorganisms being capable of completely dechlorinating PCE to ethylene may be present in the Changwon B site aquifer. In this study we find that complete PCE reductive dechlorinators are present at some PCE-contaminated sites in Korea. In an engineering point of view this information makes it feasible to apply a biological reductive dechlorination process for remediating PCE- and/or TCE-contaminated aquifers in Korea.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.597-602
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• 2005

Quality factors of emulsified ginseng drink were determined during storage at various temperatures, and its shelf-life was predicted based on changes in emulsion stability, acidify, viscosity, and yellowness. Viscosity was highly dependent on storage temperature. Emulsion stability changed rapidly during early storage period (1st step), then slowly thereafter (2nd step). $Q_{10}$ values of emulsion stability were 2.50 and 1.38 for 1st and 2nd steps, respectively. Viscosity, acidity, and yellowness showed $Q_{10}$ values of 3.45, 1.77, and 1.99, respectively. Although $Q_{10}$ value of 2 has been generally used to predict shelf stability of food materials, our results suggest adopting same $Q_{10}$ value to predict shelf stability of emulsified ginseng drink is not appropriate.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.681-686
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• 2011

The aim of this study was to investigate the distribution of soil biota across forest types and soil depths in Gwangneung Experimental Forest. We selected 5 sites, which are 3 deciduous- and 2 coniferous forests. The abundance of microflora in these areas was analyzed by the phospholipid fatty acid (PLFA) indicators, and the density of mesofauna was measured by the abundance of nematodes and microarthropods. The abundance of soil microflora was higher in the A layer than in the B layer based on the PLFA indicators, but there were no differences between deciduous and coniferous forests. Average density of nematodes was higher in the A horizon than in the B horizon. The density of fungivorous nematodes was higher in the deciduous forests. Mean densities of Collembola and Oribatida were 44% and 42% of microarthropods in soil samples, respectively. The results of microbial PLFA indicators were significantly correlated with the density of their consumers, which reflected that the food web in fungi- and bacteria-based soil developed in this forests. This study suggested that the distribution of soil organisms largely separated by soil depths and was slightly affected by the forest type in the Gwangneung Experimental Forest.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.354-363
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• 2012

The study was conducted to determine bio-markers and establish shelf-life for eggs and egg products. The selected biomarkers were measured storage period according to samples (two months for table eggs and two weeks for whole liquid eggs) and five storage temperatures ($10^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, $35^{\circ}C$ and $45^{\circ}C$). The bio-markers for table eggs determined pH, acid value, VBN (volatile basic nitrogen), HU (Haugh unit), aerobic plate counts, coliform group, and Salmonella sp. The bio-markers for whole liquid eggs excluded HU in the bio-markers of eggs. The shelf-life of table eggs observed as 42 d at $10^{\circ}C$, 27 d at $15^{\circ}C$, 9 d at $25^{\circ}C$, 2 d at $35^{\circ}C$, and 1 d at $45^{\circ}C$ in sensory overall acceptability. The shelf-life of pasteurized whole liquid eggs observed as 7 d at $10^{\circ}C$, 3 d at $15^{\circ}C$, 2 d at $25^{\circ}C$, 1 d at $35^{\circ}C$, and less than one d at $45^{\circ}C$ in total plate count. The shelf-life of non- pasteurized whole liquid eggs observed as 4 d at $10^{\circ}C$, 2 d at $15^{\circ}C$, 1 d at $25^{\circ}C$, and less than 1 d at $35^{\circ}C$ and $45^{\circ}C$ in total plate count.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.191-196
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• 1998

The MeOH extract from root of Pulsatilla koreana was showed antimicrobial activities against bacteria and yeast. The antimicrobial active substances of MeOH extract were successfully purified with solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified two active substances were isolated by HPLC and identified as 4-hydroxy-3-methoxycinnamic acid and 3,4-dihydroxycinnamic acid by MS, $^{1}H-NMR$ and $^{13}C-NMR$.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1115-1118
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• 2010

최근 실내공기질에 대한 관심이 높아지면서 실내공기질을 쾌적하게 유지하기 위한 다양한 기술에 대한 연구가 활발히 이루어지고 있다. 기존에는 미세먼지와 부유미생물 등이 가장 중요한 오염물질이었으나, 최근에는 이산화탄소가 크게 각광받고 있다. 이산화탄소는 그 자체가 환기의 지표이기도 하지만, 최근의 저탄소 녹색성장 기조에 따라 환기에 의한 냉난방 에너지 비용을 절감하는 방안에 대한 관심도 크게 높아지고 있다. 본 연구에서는 제올라이트를 이용하여 실내공간의 이산화탄소를 제어하는 방안에 대하여 기술하였다. 소형 lab-scale의 이산화탄소 흡착성능 평가시스템을 제작하고, 이를 이용하여 제올라이트의 이산화탄소의 흡착성능을 알아보았다. 또한, 본 시스템의 실용화를 위해서는 이산화탄소가 흡착한 제올라이트의 재생이 필요한데, 이를 위하여 다양한 온도와 압력 등의 조건 하에서 이산화탄소의 탈착성능을 TSA/PSA를 이용하여 알아보았다. 흡착실험을 통하여 제올라이트를 이용한 실내공간용 이산화탄소의 저감 효과를 확인할 수 있었다. 그러나, 탈착실험 결과 2~5회 정도 열탈착 시킨 후에는 이산화탄소의 흡착 성능이 현저하게 감소하여, 이를 개선하기 위한 방안의 개발이 필요함을 알 수 있었다.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.55-60
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• 2002

In order to investigate the microbiological contamination of spring water, we performed the standard plate count, coliform and psychrotrophilic bacteria in 109 spring waters in Seoul. Of 109 spring waters, geometirc mean standard plate count was 0.19 CFU/ml, and the highest in Mt. Boolam, 4..43 CFU/ml and Mt. Dobong, 3.86 CFU/ml, but not detected in Mt. Woomyun and Mt. Cheonggye. Four spring waters have shown over 100 CFU/ml in standard plate count. The geometric mean psychrotrophilic bacteria was 49.2 CFU/ml, the most prevalent spring water was Mt. Nam, 125 CFU/ml, the lowest Mt. Woomyeun. Among a total of 109, coliform was detected from 21 spring waters(19.3%) and the geometric mean of coliform was 0.005 MPN/100ml. The isolated genera of coliform were 7 isolates of E. coli(33%), 5 Klebsiella(24%), 4 Enterobacter(19%), 3 Citrobacter(14%) and 2 Serratia(10%), respectively. The 22 spring waters(20.2%) failed to meet the standard limits of drinking water based on regulation in Korea. The inappropriate rate of standard plate count in spring water was 4.5%, that of coliform was 81.1% and both of them was 13.6%. There was the significant correlation between standard plate count and psychrotrophilic bacteria in spring water(r=0.95, p<0.01).

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.164-168
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• 2014

The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.259-266
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• 2015

Observed trends in climate change, globalization and an aging population have an effect on public health conditions in Korea, prompting a reevaluation of current environmental regulations. In this study, we evaluated the performance of the total coliform (TC) standard, which is the only microbiological standard in the current regulation regime for hot spring water, by estimating correlation with the presence/absence of Legionella, a non-fecal opportunistic pathogen with heat-tolerance. Microbiological data in 7 studies that surveyed Legionella in hot spring waters were subjected to meta-analyses with the odds ratio (OR) as the effect size. The presence/absence of Legionella was significantly correlated to TC levels [OR = 3.1(1.5–6.4, 95% CI), p = 0.002]. Due to there being no direct explanation as to the reason for the occurrence of TC, mesophilic fecal bacteria, being coupled with Legionella presence, the mechanism of the correlation between the two kinds of bacteria was further investigated. Legionella presence was more prevalent with a high heterotrophic plate count [HPC; 4.0(2.2–7.2); p < 0.001] and water temperature [4.3(1.4–13.6), p = 0.011] when the temperature range was <40℃. However, it was reverse-correlated with water temperature when the temperature was >50℃ [0.2(0.1–0.4), p < 0.001]. Therefore, bacterial standing crops in hot spring waters appear to be determined by water temperature in general, and this forces TC and Legionella levels be correlated. In accordance with this relationship, HPC rather than TC reflect the levels of non-fecal contamination better. Therefore, employing HPC as the sole microbiological standard, or adding HPC into the current standard of hot spring water assessment, is suggested as a proactive measure to prevent health issues arising from contamination.