• 제목/요약/키워드: MPN(the most probable number)

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어육에 접종한 위생지표세균의 동결저장중 변화 (Survival of Sanitary Indicative Bacteria Inoculated in Fish Muscle Homogenates during Freezing and Frozen Storage)

  • 최종덕;장동석;김영만
    • 한국수산과학회지
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    • 제19권4호
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    • pp.356-362
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    • 1986
  • This experiment was designed to evaluate effects of freezing and frozen storage on survival of sanitary indicative bacteria in seafoods. Culture of bacteria such as Escherichia coli type I, Citrobacter freundii type I, Klebsiella aerogenes type I and Streptococcus faecalis was inoculated into homogenates of pollack, shrimp, and sardine frozen in a contact plate freezer at $-40^{\circ}C$ and chest freezer at $-20^{\circ}C$, stored at $-20^{\circ}C$, and then survival of the inoculated bacteria was determined over a period of 95 days. Coliform group was highly sensitive to freezing and frozen storage showing survival of about $2\%$ after 95 days of frozen storage at $-20^{\circ}C$, whereas Streptococcus faecalis was relatively resistant with $20\%$ survival rate. The sanitary indicative bacteria count was rapidly decreased in the early stage of frozen storage revealing 90 to $95\%$ loss of coliform group and 40 to $70\%$ loss in case of Streptococcus faecalis after 10 days storage. In determining recovery rate, most probable number (MPN) method gave more reproducible recovery of the tested strain than did the selected agar plate method.

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Molecular and Ecological Analyses of Microbial Community Structures in Biofilms of a Full-Scale Aerated Up-Flow Biobead Process

  • Ju, Dong-Hun;Choi, Min-Kyung;Ahn, Jae-Hyung;Kim, Mi-Hwa;Cho, Jae-Chang;Kim, Tae-Sung;Kim, Tae-San;Seong, Chi-Nam;Ka, Jong-Ok
    • Journal of Microbiology and Biotechnology
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    • 제17권2호
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    • pp.253-261
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    • 2007
  • Molecular and cultivation techniques were used to characterize the bacterial communities of biobead reactor biofilms in a sewage treatment plant to which an Aerated Up-Flow Biobead process was applied. With this biobead process, the monthly average values of various chemical parameters in the effluent were generally kept under the regulation limits of the effluent quality of the sewage treatment plant during the operation period. Most probable number (MPN) analysis revealed that the population of denitrifying bacteria was abundant in the biobead #1 reactor, denitrifying and nitrifying bacteria coexisted in the biobead #2 reactor, and nitrifying bacteria prevailed over denitrifying bacteria in the biobead #3 reactor. The results of the MPN test suggested that the biobead #2 reactor was a transition zone leading to acclimated nitrifying biofilms in the biobead #3 reactor. Phylogenetic analysis of 16S rDNA sequences cloned from biofilms showed that the biobead #1 reactor, which received a high organic loading rate, had much diverse microorganisms, whereas the biobead #2 and #3 reactors were dominated by the members of Proteobacteria. DGGE analysis with the ammonia monooxygenase (amoA) gene supported the observation from the MPN test that the biofilms of September were fully developed and specialized for nitrification in the biobead reactor #3. All of the DNA sequences of the amoA DGGE bands were very similar to the sequence of the amoA gene of Nitrosomonas species, the presence of which is typical in the biological aerated filters. The results of this study showed that organic and inorganic nutrients were efficiently removed by both denitrifying microbial populations in the anaerobic tank and heterotrophic and nitrifying bacterial biofilms well-formed in the three functional biobead reactors in the Aerated Up-Flow Biobead process.

측정방법에 따른 장염비브리오균의 검출율의 비교 (DIFFERENCES IN VIBRIO PARAHAEMOLYTICUS DETECTION RATIO BY ANALYTICAL METHODS)

  • 장동석;김영만
    • 한국수산과학회지
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    • 제11권1호
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    • pp.19-24
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    • 1978
  • 장염비브리오균 검사에 있어서 검출방법에 따른 검출율은 차이를 알아보기 위하여 부산지방을 중심으로 해수 298개 시료, 112개 시료, 패류 169개 시료 어류 80개 시료 총 659개 시료를 단일 시험관을 사용하였을 때와 다수의 시험관을 사용하였을 때, 원시료 또는 일단계희석하였을 때의 검출율를 비교 실험한 자료를 분석 검토하여 그 결과를 요약하면 다음과 같다. 1. 해수에 있어서 10 ml를 접종 배양할 때에 장염비브리오균 음성인데도 같은 시료에서 1/100 는 1/1000로 희석한 시료에서 장염비브리오균 양성으로 나타나는 경우가 많았다. 이러한 현상은 이토, 패류, 어류에서도 같은 경향이었다. 2. 총 659개 시료 중에서 $52\%$에 해당하는 343개 시료가 장염비브리오균 양성으로 판정되었는데 이중희석하지 않은 시료에서 이 균이 검출된 것은 $22.5\%$인 149개 시료에 불과하였다. 시료별로 보면 해수는 $50\%$$24.5\%$, 이토의 경우는 $65.2\%$$28.6\%$, 패류에서는 $56.2\%$$22.5\%$에 불과하였다. 3. 최확수법에 의한 장염비브리오균 검출율은 단일희석법으로 측정했을 경우의 2배 이상이었다. 4. 3개 시험관을 사용한 최확수법에 있어서 제일 낮은 희석단계에서 양성으로 판정된 것은 $28.9\%$, 3개의 시험관 모두가 양성인 것은 $9.4\%$뿐이었다.

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시화호 저니(Sediment)에서의 유기물 및 중금속 농도와 혐기성호흡세균과의 상관관계 (Relationship between the Organic Content, Heavy Metal Concentration and Anaerobic Respiration Bacteria in the Sediments of Shiwha-ho)

  • 현문식;장인섭;박형수;김병홍;김형주;이홍금;권개경
    • 한국미생물·생명공학회지
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    • 제27권3호
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    • pp.252-259
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    • 1999
  • Anoxic sediments collected from Shiwha-ho area were used to find the relationship between the heavy-metal, organic content and anaerobic respiration bacteria by most probable number (MPN) method. Analysis of the sediments showed that COD content was higher in the sediments collected from Ansan-cheon and Shiwha-ho than those collected from sea area nearby. Particularly noticeable was the fact that heavy metal concentration was much higher in the sediments of Shiwha-ho area contaminated by heavy-metal, although they were rich in electron donor and electron acceptor for Fe(III)-reducing bacteria using lactate as an electron donor was in the range of 1.1$\times$106-4.6$\times$107MPNs/ml in the sediments collected from the sea-side of the lake, which were lower in heavy-methal concentration and higher in Fe-Mn content than those from other region. The number of Fe(III)-reducing bacteria using acetate as an electron donor was in the rang eof 4.3$\times$102-8.1$\times$105MPNs/ml in the same sediments. Chromate-reducing bacteria were more populated(4.6$\times$104-8.1$\times$105MPNs/ml) in the sediments contaminated by heavy metals. The number of sulfate-reducing bacteria wee counted in the sediments collected from the more contaminate inner-side than those from the sea-side of the lake.

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Microbial contamination including Vibrio cholerae in fishery auction markets in West Sea, South Korea

  • Choi, Yukyung;Lee, Yewon;Lee, Soomin;Kim, Sejeong;Lee, Jeeyeon;Ha, Jimyeong;Oh, Hyemin;Shin, Il-Shik;Yoon, Yohan
    • Fisheries and Aquatic Sciences
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    • 제22권11호
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    • pp.26.1-26.7
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    • 2019
  • Background: The monitoring of pathogens of fishery auction markets is important to obtain safe fishery products regarding hygiene and sanitation. In this study, aerobic, coliform, Escherichia coli, and Vibrio cholerae were monitored in the fishery products and environmental samples obtained from fishery auction markets. Methods: The fishery products (flounder, octopus, skate, rock cod, sea bass, snail, monkfish, flatfish, comb pen shell, corb shell, conger eel, hairtail, croaker, and pilchard) were placed in filter bags, and the environmental samples (samples from the water tanks at the fishery auction markets, seawater from the fishery distribution vehicles, ice from wooden or plastic boxes, and surface samples from wooden and plastic boxes used for fish storage) were collected. Aerobic bacteria, E. coli, and coliform in the samples were enumerated on aerobic count plates and E. coli/coliform count plates, respectively. For V. cholerae O1 and V. cholerae non-O1 quantification, most probable number (MPN)-PCR analysis was performed. Results: Aerobic and coliform bacteria were detected in most samples, but E. coli was not detected. Wooden boxes were contaminated with high levels of aerobic and coliform bacteria in all seasons (spring, summer, and fall). During fall, V. cholerae non-O1 were detected in snails, hairtails, croakers, flatfishes, pilchards, plastic boxes, and water samples. Conclusions: These results indicate an increased prevalence of V. cholerae contamination in fishery products in fall, including food contact samples, which can be vehicles for cross-contamination.

Seasonal variation of physicochemical factor and fecal pollution in the Hansan-Geojeman area, Korea

  • Park, Young Cheol;Kim, Poong Ho;Jung, Yeoun Joong;Lee, Ka Jeong;Kim, Min Seon;Go, Kyeong Ri;Park, Sang Gi;Kwon, Soon Jae;Yang, Ji Hye;Mok, Jong Soo
    • Fisheries and Aquatic Sciences
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    • 제19권4호
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    • pp.17.1-17.9
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    • 2016
  • The seasonal variation of fecal coliforms (FCs) and physicochemical factors was determined in seawaters of the Hansan-Geojeman area, including a designated area for oyster, and in inland pollution sources of its drainage basin. The mean daily loads of FCs in inland pollution sources ranged from $1.2{\times}10^9$ to $3.1{\times}10^{11}$ most probable number (MPN)/day; however, the pollutants could not be reached at the designated area. FC concentrations of seawaters were closely related to season, rainfall, and inland contaminants, however, within the regulation limit of various countries for shellfish. The highest concentrations for chemical oxygen demand (COD) and $chlorophyll-{\alpha}$ in seawaters were shown in the surface layer during August with high rainfall, whereas the lowest for dissolved oxygen (DO) in the bottom layer of the same month. Therefore, it indicates that the concentrations of FC, COD, DO, and $chlorophyll-{\alpha}$ of seawaters were closely related to season and rainfall.

경주시를 관류하는 하천수에 대한 세균학적 조사 - 살모넬라에 대하여 - (The Bacteriological Survey of the Main Streams in Kyong-Ju City - on Samonellae -)

  • 최익한
    • Journal of Preventive Medicine and Public Health
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    • 제22권2호
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    • pp.268-275
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    • 1989
  • 1988년 6, 7월 2개월간 경주시내를 관류하는 주요 하천수의 16개 지점을 선정하어 2주 간격으로 채수하여 일반세균수, 최확수 및 병원성 장내세균중 Salmonella 검출을 시도한 결과 얻은 성적을 요약하면 다음과 같다. 1. 일반세균수 측정결과 6월에는 오릉교지점이 비교적 낮게 측정되었고($1.1{\times}10^2/ml,\;1.58{\times}10^4/ml$), 서천교 및 형산강 합류점이 가장 높게 측정되었다. ($5.3{\times}10^4/ml,\;4.1{\times}10^4/ml,\;8.2{\times}10^5/ml,\;5.7{\times}10^5/ml$). 7월 1차에서는 보문교지점에서 $1.1{\times}10^5/ml$으로 가장 낮게 2차에서는 서천교지점이 $8.4{\times}10^4/ml$으로 가장 낮고, 보문호지점에서 $7.4x10^6/ml$으로 가장 높게 측정되었다. 2. 최확수 측정결과에서 6월 1, 2차 측정 모두 1,600으로 높게 나온 지점은 문천교, 월성교, 고훈교등 3지점이었으며 7월 1, 2차 측정 모두 1,600이상으로 나온 곳은 문천교, 월성교, 고훈교, 신평교, 경주교, 형산강 합류점등 총 6지점 이었으며, 이중 문천교, 월성교, 고훈교, 경주고등 4지점은 2,400이상으로 측정되었다. 3. Salmonellar 군의 분리성적은 총 212균주 중에서 76주(35.8%)가 Salmonella 군으로 동정되었고 이중에서 Salmonella typhi 5주(2.36%), Salmonella paratyphi A는 5주(2.36%), Salmonella paratyphi B는 3주(1.42%), 기타 Salmonella군은 63주(29.72%)로 분리 동정되었다.

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Comparison of TEMPO BC and MYP Plate Methods for the Enumeration of Bacillus cereus in Various Foods

  • Lee, Da Yeon;Kim, Hee Yeon;Cho, Yong Sun
    • 한국식품위생안전성학회지
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    • 제32권4호
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    • pp.249-253
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    • 2017
  • 본 연구는 자동화 MPN 분석 장비인 TEMPO (TEMPO BC)와 MYP 배지법을 이용한 바실러스 정량 시험 결과에 대한 상관관계와 유의성을 연구하였다. 자연적으로 오염되어 있는 B. cereus 다빈도 검출 식품을 선별하여(N = 384) 두 시험법으로 정량 시험한 결과값의 차가 1 log CFU/g 미만이 95.3%였으며, B. cereus가 검출된 시료에서는 92.5%였다. 통계학적으로 TEMPO BC 시험법과 MYP 배지법은 유의적 차이가 없었다(p < 0.05). 국내 정량 규격이 있는 식품에 인위적으로 B. cereus를 접종하고 두 시험법을 비교하였다. $R^2$값은 소스류(0.98), 조림식품류(0.98), 젓갈류(0.96)에서 유의적인 차이가 없었으나, 생식류(0.94), 청국장류(0.86), 된장류(0.71)는 시험법 간의 유의적인 차이가 있었다. 콩, 메밀 등의 곡류 제품은 TEMPO BC 결과값의 오류가 날 수 있는 재료로 명시되어 있으므로 선식류와 청국장류, 된장류는 자동화 시험법인 TEMPO BC로 사용하기 위해서는 시험법을 추가적으로 검증 할 필요성이 있다고 생각된다. 자연적으로 오염되어 있는 식품 시료와 인위적으로 접종한 시료에 대한 선형 방정식은 $log(TEMPO\;BC)=0.8453{\times}log$ (MYP배지) + 0.1642이며 paired t-test를 이용하여 검증한 결과 유의적인 차이가 없었다. 최근 식품의 안전성에 대한 소비자의 관심이 증가하여 식품공전 및 국제 기준에 정량기준이 강화되고 있는 추세이므로 TEMPO BC의 수요증가가 예상된다. 따라서 본 연구는 이에 대비하여 식품의 안전성 평가에 사용되는 기존의 실험법과의 비교 및 타당성 연구 기초 자료로 쓰일 것이라 생각된다.

광어(Paralichtys olivaceus)의 스쿠치카감염증(感染症) -스쿠치카섬모충(纖毛蟲)의 배양성상(培養性状).약제감수성(藥劑感受性).병원성(病源性)-

  • 길수 수;일향진일;오 명주;생도삼내자;목촌교구;삼 립성;야촌철일;회면량남
    • 한국어병학회지
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    • 제6권2호
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    • pp.205-218
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    • 1993
  • On the development of hirame(Paratichtys olivaceus) culture, outbreak of scuticociliata infection was reported to cause severe damage in Japan. To establish effective measures for isolation and cultivation of this ciliate, we tried to culture this pathogenic ciliate using medium for bacteria and fish cell lines in vitro. Scuticociliata from the brain tissues of infected fish was aseptically inoculated to CHSE-214 cells cultured in MEM-10 without antibiotic. Scuticociliata grew well and the number of ciliate reached $10^6\;cells/ml$ at temperatures of $15^{\circ}C$ to $20^{\circ}C$ for 10d. The number of ciliate cultured in the cell lines is 10 times higher than the numbers cultured in the liquid medium alone. This ciliata could be cloned by dilution method. Scuticociliata isolated could grow well on 42 different cell lines that were established from marine fish, warm freshwater fish, and salmonids. This ciliate could be preserved in liquid nitrogen for more than 6 months. Subsequently, we observed the optimal temperature and salinity for growth, and tested the sensitivities of this organism to formaldehyde, flagyl(Metronidazole), Ekuteshin(Combination compound of sulfamonometoxin and ormethoprim), and ozonixation. Optimal temperature for growth was $25^{\circ}C$ and salinity was 1.0 to 1.5%. Washed scuticociliata was killed by formaldehyde at the concentration of 50ppm for 10min, but was not completely killed even at a high concentration of 400ppm for 20min in MEM-5. Flagyl and Ekuteshin can inhibit the growth of scuticociliata at the concentration of 1,000 and $100{\mu}g/ml$ in MEM-10, respectively. More than 99% of this scuticociliata could be killed by ozonization at a dose equivalent to $1.0mg/\ell$ oxidant for 30sec in sea water. Isolated scuticociliata showed the pathogenicity to the cultured hirame by artificial infection(I. P. injection, $10^5\;cells$/fish). The number of scuticociliata in the water could be counted by most probable number(MPN) method using tissue culture, and the minimum detectable number was $1.8\;cells/\ell$. The number in the reservoir tank for water supply to the culture tank was 110 cells/l. After cleaning by elimination of the sediments from of the reservoir tank and disinfected with formaldehyde, number of scuticociliata decreased and was counted less than $1.8\;cells/\ell$ and infection rate of cultured hirame was decreased.

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국내(國內) 초지토양(草地土壤)에 분포(分布)한 Rhizobium meliloti의 질소고정력(窒素固定力)과 항균제반응(抗菌劑反應) 특성(特性) (Symbiotic effectiveness and intrinsic antibiotic resistance of Rhizobium meliloti populated in Korean pasture soils)

  • 강위금;하호성;정연태
    • Applied Biological Chemistry
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    • 제35권3호
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    • pp.179-185
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    • 1992
  • 우리나라 남부지방(南部地方)의 5개(個) 산지(山地) 목초지(牧草地)에 분포한 알팔파근류균(根瘤菌) R. meliloti의 밀도(密度)와 실소고정력(室素固定力), 그리고 항생제(抗生劑) 반응(反應) 특성(特性)을 조사하였다. 그 결과(結果), 초지토양(草地土壤)에 분포한 R. meliloti 밀도(密度)는 $1.7{\times}10^2\;cells/g$.토양(土壤)(여주시(麗州市) 충효동(忠孝洞)) 내지 $1.0{\times}10^5\;cells/g$.토양(土壤)(경주군(慶州郡) 감포면(甘浦面)) 수준(水準) 이었으며, 토양 pH와는 정(正)의 상관(相關)을 보였다. 그리고, 초지토양(草地土壤)의 알팔파 접종효과(接種效果)로 본 토착(土着) R. meliloti의 질소고정력(窒素固定力)은 전반적으로 표준균주(標準菌株)인 TAL 접종제(接種劑) 보다 저조(低調)하였으나, 달성군(達城郡) 옥포면(玉浦面) 초지(草地)에서 분리(分離)된 YCKa 539, YCKa 542 2균주(菌株)는 비슷하거나 우수(優秀)한 질소고정력(窒素固定力)을 보였다. 초지토양별로 보면 경주군(慶州郡) 견곡면(見谷面)의 것이 가장 높았고, 다음으로 달성군(達城郡) 옥포(玉浦)>경주시(慶州市) 충효(忠孝)>달성군(達城郡) 화국(花國)>경주군(慶州郡) 감포(甘浦) 균주(菌株) 순(順)이었다. 분리균주(分離菌株)들은 항생제(抗生劑) Ery($100\;{\mu}g/ml$), Nal($160\;{\mu}g/ml$), Str($10\;{\mu}g/ml$)에 대해 각각(各各) 67%, 77%, 80%정도의 내성경향(耐性傾向)을 보이면서 전체적으로는 14개(個)의 항생제(抗生劑) 내성류형(耐性類型)으로 분류(分類)되었는데, 이들 류형(類型)과 균주(菌株)의 질소고정력간(窒素固定力間)에는 뚜렷한 관계경상(關係傾商)을 보이지 않았다. 그리고, 분리균주(分離菌株) 중(中)에서 질소고정력(窒素固定力)이 가장 우수(優秀)하였던 YCKa 542균주(菌株)는 Ery Nal, Neo, Str 내성인 X번형(番型)에 속하였다.

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