• 한국물환경학회지
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• 제25권1호
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• pp.76-83
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• 2009

In 2005, the 5.84-Km length of Cheonggyecheon stream, previously covered with concrete road, was uncovered in the middle of Seoul, Korea. We investigated microbial water quality in various sites in Cheonggyecheon stream. We took water samples on three different days. The sampling sites included inflow water from upper stream (Mojeongyo), midstream (Ogansugyo), and downstream (Muhakgyo). Fecal pollution indicator microorganisms were measured by both IDEXX $Colilert^{(R)}$ and $Enterolert^{(R)}$. Microbial community from these sampling sites was also characterized based on 16S rRNA gene sequences. The average concentrations of total coliform are 5 CFU/100 mL, 1474 CFU/100 mL, and 1776 CFU/100 mL at Mojeongyo, Ogansugyo, and Muhakgyo, respectively. The average concentrations of fecal coliform were 28 CFU/100 mL, 47 CFU/100 mL in Ogansugyo, and Muhakgyo, respectively. The concentrations of other fecal indicator microorganisms including E. coli and Enterococcus sp. increased in downstream. When we characterized the microbial community, unique microbial community were discovered at different sampling sites. This study suggests that Cheonggyechoen stream is likely affected by non-point fecal sources and has unique microbial environment as the river flows downstream.

• 한국물환경학회지
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• 제25권1호
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• pp.69-75
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• 2009

Water stress has become a major concern in agriculture. Korea suffers from limited agricultural water supply, and wastewater reuse has been recommended as an alternative solution. A study was performed to examine the effects of microorganism concentration in the ponded-water of a paddy rice field with reclaimed-water irrigation for evaluating the microbial risk to farmers and neighborhood children. Most epidemiological studies were performed based on an upland field, and they may not directly applicable to paddy fields. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion. Their risk value increased significantly high level after irrigation and precipitation. It implies that agricultural activities such as plowing, and fertilizing, and precipitation need be practiced a few days after irrigation considering health risks. The results about field application of the microbial risk assessment using E. coli showed difference according to monitoring time and treatment plot. Result of the microbial risk assessment showed that risk values of ground-water and reclaimed secondary wastewater irrigation were lower than directly use of wastewater treatment plants' effluent. This paper should be viewed as a first step in the application of quantitative microbial risk assessment of E. coli to wastewater reuse in a paddy rice farming.

• 한국토양비료학회지
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• 제44권2호
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• pp.221-227
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• 2011

논 토양에서 청보리, 자운영과 트리티케일을 시용하고 벼생육초기에 토양 미생물 생태계의 변화에 미치는 영향을 검토하였다. 녹비를 시용한 처리구는 관행에 비해 토양 유기물 함량은 유의적으로 증가하였으나 토양의 나트륨 함량은 유의적인 감소를 나타냈다. 내생균근균의 함량과 구성비율은 녹비 시용으로 관행 보다 유의적으로 높아졌으며 특히 청보리 처리구가 가장 높았다. 또한 토양의 그람음성 세균과 그람양성 세균의 비율과 불포화지방산과 포화지방산 함량의 비율은 청보리 처리구가 다른 처리구에 비해 유의적인 증가를 보였다. 그리고 주성분 분석에서 PC 1에 가장 큰 영향을 미친 미생물 군집은 그람음성 세균인 것으로 나타났으며 청보리 처리구는 관행과 가장 큰 차이를 나타냈다. 이러한 결과를 종합한 결과 청보리는 논 토양의 초기 미생물 다양성을 증대시킬 수 있는 최적의 녹비작물로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권5호
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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 Nutrition and Health
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• 제18권4호
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• pp.283-292
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• 1985

대학 급식 시설의 위생 실태를 평가하기 위해서 오뎅국의 생산 과정을 통한 소요시간 및 온도상태 측정 pH 및 Aw측정, 미생물 검사를 실시하여 HACCP model에 의해 분석, 평가한 결과는 다음과 같다. 1 )소요시간 및 온도상태 측정 결과. 재료들의 조리후 실온방치 단계와 국물의 보온단계에서 철저한 관리가 요구된다. 2 ) pH및 Aw측정 결과, 대부분의 단계가 미생물 증식에 적합한 조건이었다. 3 )음식에 대한 미생물 분석 결과, 재료들의 미생물적 품질이 대체로 낮았다. 또한 조리후 급식전 보관단계에서 장시간 실온에 방치되므로 미생물의 오염 및 증식 기회가 많았다. 4 ) 오뎅국 생산에 사용되는 기구, 설비, 용품 및 용기에 대한 미생물 분석 결과 뚝배기, 장갑, 행주와 도마에 대한 즉각적인 시정이 요구된다. 5 ) 이상에서 오뎅국 생산 단계에서의 critical control points는 재료, 전처리, 후처리 및 급식전 보관단계로 지적되었다.

• 한국식품저장유통학회지
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• 제15권5호
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• pp.769-773
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• 2008

삼계용 닭에 이산화염소수를 농도별로 처리하여 미생물에 대한 살균효과 및 품질에 관련된 이화학적 특성 변화를 연구하였다. 삼계용 닭의 냉장저장 초기 총 호기성 세균은 대조구 4.14 log CFU/g이었고, 50 ppm 처리 시 0.41 log cycle, 100 ppm 처리 시 0.73 log cycle 감소함을 나타냈으며, 이산화염소수 처리 농도 증가에 비례하여 감소하였다. 저장 10일째 총 호기성 세균수는 이산화염소수 100 ppm 처리시 3.41 log CFU/g에서 6.07 log CFU/g으로 증가한 반면, 대조구는 4.14 log CFU/g에서 6.92 log CFU/g으로 증가하여 저장 기간 동안 대조구와 처리구간의 유의적인 차이를 보였다. pH 와 VBN 값은 저장기간이 증가할수록 증가하였고 처리구와 대조구 간에 유의차를 보이지는 않았다. 관능검사 결과는 삼계용 닭이 저장 7일 이후에는 부패가 진행됨을 보였고, 이산화염소수 처리 농도가 증가할수록 평가점수가 높음을 확인하였다. 따라서, 이산화염소수 처리가 삼계용 닭의 미생물학적 안전성 증진과 저장성 증대에 도움을 준다고 판단된다.

• 한국환경보건학회지
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• 제34권1호
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• pp.86-94
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• 2008

Lake Shiwha, an artificial lake located near metropolitan Seoul, offers a unique water environment and has been suspected to have high levels of chemical and microbiological contaminations. Lake Shiwha was originally connected to the sea but currently has four major surface water inputs from agricultural, municipal, industrial areas and in addition an occasional inflow from the sea. The objectives of this study are to investigate the relative contribution of microbial contaminants from each of the inflowing surface waters and to identify appropriate microbial indicator organisms in this unique water environment. We measured the levels of microbial contaminations in the four inflowing surface waters. A number of microbial indicator organisms including total coliform (TC), fecal coliform (FC), E. coli, Enterococci, somatic and male-specific coliphages were analyzed. Bacterial indicator microorganisms were detected and quantified by the $Colilert^{(R)},\;Enterolert^{(R)}$ kit. Surface water (50 l) was sampled by $ViroCap^{TM}\;5"$ cartridge filters and analyzed by the single agar layer method for detecting coliphages. The concentrations of TC, FC, E. coli, and Enterococci were 1543 CFU/100 ml${\sim}1.99{\times}10^6$ CFU/100 ml, 0 CFU/100 ml${\sim}202$ CFU/100ml, 0 CFU/100 ml${\sim}1.80{\sim}10^5$ CFU/100ml, 74 CFU/100 ml${\sim}3408$ CFU/100 ml, respectively. The male-specific and somatic coliphages were detected in three different inflowing surface waters. Isolated E. coli and Enterococci strains were further analyzed by 16s rDNA amplification and subsequent phylogenetic analysis from Jungwang-chun, Ansan-chun, Banwol-chun and penstock of inflowing surface water. Our results indicated that the concentrations of different fecal indicator microorganisms might not be highly correlated with each other. Multiple microbial indicator organisms should be used for monitoring microbial contamination and microbial source tracking methods.

• 한국식품위생안전성학회지
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• 제12권2호
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• pp.111-116
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• 1997

For the purpose of improving hygienic quality of dried-Angelica Keiskei Koidz powder, the effect of ozone treatment and gamma irradiation on the microbial decontamination and physicochemical properties were investigated. Gamma irradiation at 5 to 7.5 kGy resulted in sterilizing total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the total aerobic bacteria of the sample. The physicochemical properties of the sample were not changed by gamma irradiation up to 7.5 kGy, whereas, ozone treatment caused remarkable changes in pH, TBA value, chlorophyll, carotenoid and fatty acid compositions. Therefore, this investigation demonstrated conclusively that gamma irradiation was more effective than ozone treatment for decontaminating and sterilizing the dried-Angelica Keiskei Koidz powder, with minimal effect on the physicochemical properties analyzed.

• 한국식품영양과학회지
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• 제26권3호
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• pp.465-467
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• 1997

The comparative effects of ozone treatment and gamma irradiation on the sterilization, physicochemical properties and sensory quality of red pepper powder were investigated. As for the sterilization of microorganisms, 7.5~10 KGy of gamma irradiation completely eliminated the coliforms, yeast and molds, and total aerobic bacteria. On the other hand, ozone treatment failed to eliminate the highly contaminated microbial load, especially total aerobic bacteria. The physicochemical properties including capsaicin, capsanthin, browning, fatty acid compositions and sensory quality were not significantly changed by gamma irradiation up to 10 kGy, whereas ozone treatment caused significant changes in fatty acid compositions and destruction of natural pigments (p<0.05). The above results led us to conclude that gamma irradiation was more effective than ozone treatment for the sterilization and maintenance of physicochemical and sensory qualities of red pepper powders.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.201-202
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• 2003

Recently, probiotics is applied for aquaculture management as an alternative method of antibiotics. Probiotics is defined as a live microbial feed supplement which a good effect to the host animal by improving its microbial condition of gastrointestinal tract (Fuller, 1989). Generally, probiotics affect growth and survival of cultured fish, water quality, immune system and so on (Rengpipat et al, 2000, Robertson et al, 2000). (omitted)