• 제목/요약/키워드: microbial assessment

검색결과 279건 처리시간 0.034초

미생물 위해성 평가의 용량-반응 모델에 대한 고찰 (A Review of Dose-response Models in Microbial Risk Assessment)

  • 최은영;박경진
    • 한국식품위생안전성학회지
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    • 제19권1호
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    • pp.19-24
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    • 2004
  • 미생물 위해성 평가의 용량-반응 모델은 생물학적 모델과 경험적 모델로 나눌 수 있다. 생물학적 모델은 미생물의 분포형태, 미생물에 대한 숙주의 감수성, 감염을 일으킬 수 있는 미생물 수에 대한 가정을 바탕으로 성립된 모델로서, 대표적으로 Exponential model과 $\beta$-Poisson model이 있다. 경험적 모델은 주로 화학물질의 독성을 나타내는데 이용되어 온 모델로, Weibull-Gamma model등이 있다. 여러 용량-반응 모델 중에서 실험 데이터에 적합한 모델을 걱정하는 데에는 deviance function(Y)을 이용하며, 현재 일부 식중독균에 대해서는 사람과 실험동물에서의 용량-반응 모델이 연구되어 있다.

유전자변형 작물이 토양 미생물상에 미치는 영향 (The Effects of Genetically Modified Crops on Soil Microbial Community)

  • 이기종;오성덕;손수인;류태훈;박종석;이장용;조현석;안병옥
    • 한국환경농학회지
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    • 제31권2호
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    • pp.192-199
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    • 2012
  • 유전자변형 작물을 종자로 판매하거나 식품, 사료 혹은 가공용으로 이용하기 위해서는 반드시 관련 기관의 승인을 받아야 한다. 관련부처에서는 유전자변형 작물의 승인에 앞서 환경위해성 평가 자료가 과학적으로 타당한지 검토한다. 환경위해성 평가 중 유전자변형 작물이 토양 미생물 군집에 미치는 영향은 충분히 연구되지 못한 분야이다. 최근 토양 환경내 미생물 군집의 특성을 연구하기 위한 발전된 방법들이 개발되고 있다. 배양에 의존적인 또는 비의존적인 기술에 의한 토양 미생물의 군집 특성을 조사한 연구와 유전자변형 작물의 환경위해성 평가 적용 가능성을 고찰하였다. 유전자변형 작물의 토양미생물 영향 평가는 사안별 평가 원칙에 의해 이루어져야 한다. 신뢰할 수 있고 상세한 토양 미생물 평가가 이루어지기 위해서는 다양한 분석 방법의 조합이 필요하다.

Microbial Degradation and Toxicity of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine

  • Khan, Muhammad Imran;Lee, Jaejin;Park, Joonhong
    • Journal of Microbiology and Biotechnology
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    • 제22권10호
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    • pp.1311-1323
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    • 2012
  • In the present work, current knowledge on the potential fate, microbial degradation, and toxicity of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was thoroughly reviewed, focusing on the toxicological assessment of a variety of potential RDX degradation pathways in bacteria and fungi. The present review on microbial degradation pathways and toxicities of degradation intermediates suggests that, among aerobic RDX degradation pathways, the one via denitration may be preferred in a toxicological perspective, and that among anaerobic pathways, those forming 4-nitro-2,4-diazabutanal (NDAB) via ring cleavage of 1-nitroso-3,5-dinitro-1,3,5-triazinane (MNX) may be toxicologically advantageous owing to its potential mineralization under partial or complete anoxic conditions. These findings provide important information on RDX-degrading microbial pathways, toxicologically most suitable to be stimulated in contaminated fields.

중·소하천에서 부착미생물군집의 성장에 따른 불소 제거 효과 평가 (Evaluation of Fluoride Removal Effect with Growth of Attached Microbial Community in Middle and Small Stream)

  • 김태경;류서영;박윤아;이종준;주광진;장광현;오종민
    • 환경영향평가
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    • 제27권6호
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    • pp.595-603
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    • 2018
  • 본 연구는 경기도 중소하천에서 하상의 부착미생물군집의 시간에 따른 생장 변화와 부착미생물군집의 성장에 따른 불소의 제거 효율을 파악하기 위해 수행하였다. 방류수가 유입되는 지점인 P1과 그 곳에서 약 2 km 유하한 하류 지점인 P2에서 12주 동안의 현장 모니터링을 실시하고, 조사 지점의 수질과 부착미생물군집의 생체량 분석을 진행하였다. 부착미생물군집의 성장량은 7차 조사 시점까지 증가하다 이후 탈리현상이 발생하는 것으로 관찰되었으며, 부착미생물군집의 성장에 영향을 미치는 요인으로는 유량, 유속, 영양물질(질소, 인) 등으로 조사되었다. 한편, 부착미생물군집 체내의 불소 함유량 또한 7차 조사 시기까지 증가하다 8차 시점부터 감소하는 경향을 보였다. 이는 부착미생물군집의 탈리현상에 의해 불소의 함유량 또한 감소하였음을 사사한다. 이를 통해 하천 관리의 방안으로서 부착미생물군집의 활용법에 대한 평가 및 관리에 기여할 수 있을 것으로 기대된다. 부착미생물군집을 활용한 기법의 적용 시에는 부착미생물군집의 성장에 영향을 미칠 수 있는 요인에 대한 기초 조사 및 탈리 시점에 따른 부착판 교체 방안 등이 포함되어야할 것으로 사료된다.

Quantitative Microbial Risk Assessment for Clostridium perfringens in Natural and Processed Cheeses

  • Lee, Heeyoung;Lee, Soomin;Kim, Sejeong;Lee, Jeeyeon;Ha, Jimyeong;Yoon, Yohan
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권8호
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    • pp.1188-1196
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    • 2016
  • This study evaluated the risk of Clostridium perfringens (C. perfringens) foodborne illness from natural and processed cheeses. Microbial risk assessment in this study was conducted according to four steps: hazard identification, hazard characterization, exposure assessment, and risk characterization. The hazard identification of C. perfringens on cheese was identified through literature, and dose response models were utilized for hazard characterization of the pathogen. For exposure assessment, the prevalence of C. perfringens, storage temperatures, storage time, and annual amounts of cheese consumption were surveyed. Eventually, a simulation model was developed using the collected data and the simulation result was used to estimate the probability of C. perfringens foodborne illness by cheese consumption with @RISK. C. perfringens was determined to be low risk on cheese based on hazard identification, and the exponential model ($r=1.82{\times}10^{-11}$) was deemed appropriate for hazard characterization. Annual amounts of natural and processed cheese consumption were $12.40{\pm}19.43g$ and $19.46{\pm}14.39g$, respectively. Since the contamination levels of C. perfringens on natural (0.30 Log CFU/g) and processed cheeses (0.45 Log CFU/g) were below the detection limit, the initial contamination levels of natural and processed cheeses were estimated by beta distribution (${\alpha}1=1$, ${\alpha}2=91$; ${\alpha}1=1$, ${\alpha}2=309$)${\times}$uniform distribution (a = 0, b = 2; a = 0, b = 2.8) to be -2.35 and -2.73 Log CFU/g, respectively. Moreover, no growth of C. perfringens was observed for exposure assessment to simulated conditions of distribution and storage. These data were used for risk characterization by a simulation model, and the mean values of the probability of C. perfringens foodborne illness by cheese consumption per person per day for natural and processed cheeses were $9.57{\times}10^{-14}$ and $3.58{\times}10^{-14}$, respectively. These results indicate that probability of C. perfringens foodborne illness by consumption cheese is low, and it can be used to establish microbial criteria for C. perfringens on natural and processed cheeses.

Microbial Risk Assessment of Non-Enterohemorrhagic Escherichia coli in Natural and Processed Cheeses in Korea

  • Kim, Kyungmi;Lee, Heeyoung;Lee, Soomin;Kim, Sejeong;Lee, Jeeyeon;Ha, Jimyeong;Yoon, Yohan
    • 한국축산식품학회지
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    • 제37권4호
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    • pp.579-592
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    • 2017
  • This study assessed the quantitative microbial risk of non-enterohemorrhagic Escherichia coli (EHEC). For hazard identification, hazards of non-EHEC E. coli in natural and processed cheeses were identified by research papers. Regarding exposure assessment, non-EHEC E. coli cell counts in cheese were enumerated, and the developed predictive models were used to describe the fates of non-EHEC E. coli strains in cheese during distribution and storage. In addition, data on the amounts and frequency of cheese consumption were collected from the research report of the Ministry of Food and Drug Safety. For hazard characterization, a doseresponse model for non-EHEC E. coli was used. Using the collected data, simulation models were constructed, using software @RISK to calculate the risk of illness per person per day. Non-EHEC E. coli cells in natural- (n=90) and processed-cheese samples (n=308) from factories and markets were not detected. Thus, we estimated the initial levels of contamination by Uniform distribution ${\times}$ Beta distribution, and the levels were -2.35 and -2.73 Log CFU/g for natural and processed cheese, respectively. The proposed predictive models described properly the fates of non-EHEC E. coli during distribution and storage of cheese. For hazard characterization, we used the Beta-Poisson model (${\alpha}=2.21{\times}10^{-1}$, $N_{50}=6.85{\times}10^7$). The results of risk characterization for non-EHEC E. coli in natural and processed cheese were $1.36{\times}10^{-7}$ and $2.12{\times}10^{-10}$ (the mean probability of illness per person per day), respectively. These results indicate that the risk of non-EHEC E. coli foodborne illness can be considered low in present conditions.

Soil Microbial Community Assessment for the Rhizosphere Soil of Herbicide Resistant Genetically Modified Chinese Cabbage

  • Sohn, Soo-In;Oh, Young-Ju;Ahn, Byung-Ohg;Ryu, Tae-Hoon;Cho, Hyun-Suk;Park, Jong-Sug;Lee, Ki-Jong;Oh, Sung-Dug;Lee, Jang-Yong
    • 한국환경농학회지
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    • 제31권1호
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    • pp.52-59
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    • 2012
  • BACKGROUND: Cultivation of genetically modified(GM) crops rapidly has increased in the global agricultural area. Among those, herbicide resistant GM crops are reported to have occupied 89.3 million hectares in 2010. However, cultivation of GM crops in the field evoked the concern of the possibility of gene transfer from transgenic plant into soil microorganisms. In our present study, we have assessed the effects of herbicide-resistant GM Chinese cabbage on the surrounding soil microbial community. METHODS AND RESULTS: The effects of a herbicide-resistant genetically modified (GM) Chinese cabbage on the soil microbial community in its field of growth were assessed using a conventional culture technique and also culture-independent molecular methods. Three replicate field plots were planted with a single GM and four non-GM Chinese cabbages (these included a non-GM counterpart). The soils around these plants were compared using colony counting, denaturing gradient gel electrophoresis and a species diversity index assessment during the growing periods. The bacterial, fungal and actinomycetes population densities of the GM Chinese cabbage soils were found to be within the range of those of the non-GM Chinese cabbage soils. The DGGE banding patterns of the GM and non-GM soils were also similar, suggesting that the bacterial community structures were stable within a given month and were unaffected by the presence of a GM plant. The similarities of the bacterial species diversity indices were consistent with this finding. CONCLUSION: These results indicate that soil microbial communities are unaffected by the cultivation of herbicide-resistant GM Chinese cabbage within the experimental time frame.

Biolog Ecoplate와 DGGE 방법을 이용한 알칼리화 토양의 미생물군집 변화 평가 (Assessment of the Changes in the Microbial Community in Alkaline Soils using Biolog Ecoplate and DGGE)

  • 이은영;홍선화
    • KSBB Journal
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    • 제28권5호
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    • pp.275-281
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    • 2013
  • Soil microbial community analysis of farmland soil sprayed with lye in order to use fertilizer in Nigeria was performed. As a control, two kinds of soils not sprayed with lye, located in Eungo and Lagos with general practice in agriculture was selected. Soil sprayed with lye was pH 8.25 through alkalization reaction, while the other soil samples were pH 6.22 and 5.94. Substrate utilization and species diversity index of soil sprayed with lye were low than that of the other soils with the analysis of Biolog ecoplate. As a result of principal component analysis, the relationship between three samples was low. Microbial community analysis was performed by DGGE and most of them were soil uncultured bacterium. Especially, Uncultured Acidobacteria and Uncultured Methylocystis sp., which had been isolated from the rhizosphere of soybean grown in that site were discovered in the soil sprayed with lye.