• 한국축산식품학회지
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• 제32권6호
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• pp.713-717
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• 2012

The objective of this study was to evaluate the effect of sodium habituation on thermal resistance of Staphylococcus aureus in various ready-to-heat (RTH) sauces. The strain mixture of S. aureus strains KACC10768, KACC10778, KACC11596, KACC13236 and NCCP10862 was habituated up to 9% of NaCl. The inocula of NaCl-habituated and non-habituated S. aureus were inoculated in 5 g portions of pork cutlet, meat and Carbonara sauces at 7 Log CFU/g, and the samples were vortexed vigorously. The inoculated samples were then exposed to 60 and $70^{\circ}C$ in a water-bath, and survivals of total bacteria and S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively, every 30 min for 120 min. At 60oC, the cell counts of total bacteria and the significant difference in survivals between sodium-habituated and non-habituated S. aureus were observed only in the Carbonara sauce; the tailing effect, which is the period of no reduction of bacterial cell counts, was observed in pork cutlet, meat and Carbonara sauces subjected to $60^{\circ}C$. At $70^{\circ}C$, total bacterial populations and sodium-habituated and non-habituated S. aureus cell counts in meat and Carbonara sauce also significantly decreased (p<0.05) after 30 min of heat treatment, followed by the obvious tailing effect. Sodium-habituated S. aureus cell counts in meat and Carbonara sauces were higher (p<0.05) than those of non-habituated S. aureus at $70^{\circ}C$. The results indicate that sodium habituation of S. aureus cells may increase the thermal resistance of the pathogen in RTH sauces; moreover, heating RTH sauces for a short time before serving may not sufficiently decrease the cell counts of S. aureus, particularly for sodium-habituated strain.

• 한국환경보건학회지
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• 제42권2호
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• pp.126-132
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• 2016

Objectives: This study aims to provide basic data regarding the bacterial total plate count in the atmospheric environment for related studies. Methods: Total plate count and the identification of culturable bacteria in the atmospheric environment in Incheon took place in 2015 using periodic survey. Correlationship analysis was performed between the number of culturable bacteria and environmental elements. In addition, an estimation of novel bacterial species was undertaken using the similarities and phylogenetic tree based on the 16S rRNA gene. Results: The total plate count of culturable bacteria was on average $176CFU/m^3$, and did not exceed $610CFU/m^3$ in the atmospheric environment. Periodic monthly measuring of total plate count was highest in June at $293CFU/m^3$, while the lowest was in July at $125CFU/m^3$. Furthermore, as a result of the identification of culturable bacteria, the genera Arthrobacter and Kocuria were dominant, while novel bacterial taxa that belong to the genera Chryseobacterium and Herbiconiux were separated. Conclusion: The total number of culturable bacteria from the atmospheric environment in Korea is on average $176CFU/m^3$. In addition, the genera Arthrobacter and Kocuria dominate. The presence of novel bacterial taxa are expected in the atmospheric environment, such as belonging to the genera Chryseobacterium and Herbiconiux.

• 한국식품과학회지
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• 제46권2호
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• pp.262-267
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• 2014

신선편이식품 소재인 유기농산물의 미생물 분포와 품질을 평가하기 위해서 풋고추, 상추, 토마토, 사과, 배, 쌀 등의 농산물을 47개 지역에서 관행농 농산물과 동시에 현장에서 시료를 수집하였다. 일반 세균수로는 유기농 고추가 평균 4.07 log CFU/g, 관행농 고추는 3.71 log CFU/g 검출되었고 상추는 유기농, 관행농에서 6.76-6.90 log CFU/g로 분석되었다. 토마토와 사과는 2종류 시료에서 각각 2.08-2.92 log CFU/g, 0.70-0.82 log CFU/g로 검출되었다. 쌀도 유기농과 관행농 시료에서 2.92-2.98 log CFU/g 범위의 세균분포를 보여주었으나 유기농 배에서는 4.48 log CFU/g, 관행농 배는 2.84 log CFU/g의 분포도를 보여 주었다. 분석시료에 따라 미생물의 분포에 많은 차이를 보여 주었으며 유기농과 관행농산물의 미생물분포는 거의 차이가 없었다. 병원성 세균인 Cl. perfringens, E. coli O157:H7, L. monocytogenes, Salmonella, S. aureus은 전혀 검출되지 않았다. 그러나 유기농산물 2개(4%)와 관행농산물 3개(6%)에서 E. coil가 1.7 log CFU/g으로 검출되었고 B. cereus는 유기농 6개(13%)가 1.97 log CFU/g수준으로, 관행농 11개(23%)에서 1.04 log CFU/g 수준으로 검출되었다. 그러므로 유기농산물과 관행농산물에서의 일반세균과 병원성 세균의 오염정도는 차이가 거의 없고 이들 병원성 미생물의 오염수준도 비교적 낮아 안전한 것으로 판단된다.

• 한국식생활문화학회지
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• 제18권5호
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• pp.428-436
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• 2003

The effect of addition with maesil(Prunus mume) juice for extending the shelf-life of wet noodle was investigated by measuring quality changes such as total microbial count and pH. The Prunus mume juice showed antimicrobial activities against Salmonella enteritidis, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. When the wet noodles containing Prunus mume juice were kept at $4^{\circ}C$ for 20 days, it was showed that the drop of pH was not significantly occurred during the storage. Total microbial counts for control exceeded the initial putrefactive criterion level of $1.0{\times}10^6\;cfu/g$ at 16 days of storage at $4^{\circ}C$. However, total microbial count of wet noodles with the addition of 10%, 20% and 30% Prunus mume juice were $3.0{\times}10^2\;cfu/g,\;3.0{\times}10^2\;cfu/g,\;and\;1.5{\times}10^2\;cfu/g$, respectively, and these bacterial counts were still less than the criterion level ever at 20 days of storage. The addition of Prunus mume juice extended the shelf-life of wet noodle appreciably.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.858-868
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• 2009

The abundance, biomass, size distribution, and taxonomic composition of bacterial and protistan (heterotrophic and autotrophic nanoflagellates and ciliates) communities were investigated in six lakes of Masurian Lake District (north-eastern Poland) differing in trophic state. Samples were taken from the trophogenic water layer during summer stratification periods. Image analysis techniques with fluorescent in situ hybridization (FISH) as well as [$^3H$]-methyl-thymidine incorporation methods were applied to analyze differences in the composition and activity of bacterial communities. The greatest differences in trophic parameters were found between the humic lake and remaining non-humic ones. The same bacterial and heterotrophic nanoflagellate (HNF) cell size classes dominated in all the studied lakes. However, distinct increases in the contributions of large bacterial (>$1.0{\mu}m$) and HNF (>$10{\mu}m$) cells were observed in eutrophic lakes. The bacterial community was dominated by the ${\beta}$-Proteohacteria group, which accounted for 27% of total DAPI counts. Ciliate communities were largely composed of Oligotrichida. Positive correlations between bacteria and protists, as well as between nanoflagellates (both heterotrophic and autotrophic) and ciliates, suggest that concentrations of food sources may be important in determining the abundance of protists in the studied lakes.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• 한국어병학회지
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• 제13권1호
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• pp.67-73
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• 2000

군산내만 해역의 해양생태계에 관한 기초자료를 얻기 위하여 금강 하구둑부터 외항까지 5개의 정점을 선정하여 종속영양 세균상의 분포를 조사하였다. 조사지역으로부터 123개의 집락을 분리-동정한 결과 Vibrio spp.(44주, 35.7%), 및 Pseudomonas spp.(42주, 34.1%), 균종이 비교적 높게 출현하였고 Aeromonas spp.(11주, 8.9%), Moraxella spp.(9주, 7.3%), Escherichia coli.(6주, 4.8%), Bordetella spp.(3주, 2.4%), Alkaligenesis spp.(3주, 2.4%), Flavobacterium spp.(2주, 1.6%), and Staphylococcus spp.(3주, 2.4%)등은 낮은 출현율을 나타냈다. 한편, 각 총 정점의 생균수는 $5{\times}10^3\sim1{\times}10^5$ CFU/ml이었으며, 생활 하수가 많이 유입되는 지역(정점 2.3)이 강 하구 및 외항지역보다 높은 검출율을 보였다. 이러한 결과는 도시의 생활 오.하수 및 산업 부산물 등의 유입으로 내만의 수질 악화가 지속적으로 진행되고 있는 것으로 추정된다. 따라서 양식사업에 있어서 문제시 되고 있는 어류의 세균성 질병의 발생이 증가될 것으로 사료되어진다.

• 한국축산식품학회지
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• 제18권3호
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• pp.232-239
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• 1998

This experiment was conducted to investigate radurization effects of gamma ray and electron beam irradiation at 1.5 and 3.0 kGy on beef steaks during 8 days of storage at 5$^{\circ}C$. Total bacteria count, psychrotrophs, mesophiles and thermophiles were analyzed at 2 days intervals. Nonirradiated beef steak was used a scontrol Total bacteria counts, psychrotrophs, mesophiles and thermophiles of the control samples showed 3.03∼4.72 logCFU / g at 0 day and increased to 7.67∼10.90 logCFU / g during 8 days storage except thermophiles. Total bacteria counts, psychrotrophs and mesophiles of beef steaks at 8 days were significantly (p＜0.05) decreased to 3.61∼5.43 logCFU / g by gamma ray and to 3.83∼7.02 logCFU / g by electron beam irradiation at 1.5 and 3.0 kGy. Thermophiles of all irradiated samples at any dose were not detectable through 8 days storage. These results suggested that both gamma ray and electron beam irradiation were effective to extend lag phase of bacterial growth of refrigerated beef. Gamma ray irradiation was better than electron beam irradiation in terms of radurization effects of beef.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.699-701
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• 2002

The current study demonstrates the ability of the marine cyanobacterium Oscillatoria willei BDU130511 to disinfect raw sewage. Within a holding time of 3 h under laboratory conditions, the organism drastically reduced in the total bacterial and coliform counts at various pH levels, in both unbuffered and buffered sewage, thereby suggesting a potential role for cyanobacteria in wastewater treatment.

• 한국수산과학회지
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• 제28권3호
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• pp.331-337
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• 1995

해조류 중 생산량이 많고 건강식품 소재로서의 가능성이 높은 미역과 다시마 해조묵을 제조하여 수침저장 중 저장 온도와 시간에 따른 생균수, pH, 적정산도, 겔강도 및 TVN의 변화를 측정하여 적정저장 조건을 검토한 결과 묵 저장 중 겔강도는 약화되었으며, TVN, 생균수는 증가하였다. 조체묵의 수침저장은 $32^{\circ}C$에서는 3일, $18^{\circ}C$ 이하에서는 15일 저장까지도 가능하였으며, 두유혼합묵은 조체묵 보다는 저장 기간이 짧아서 $18^{\circ}C$ 저장시 3일까지 가능한 것으로 판단되었다.