• 상하수도학회지
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• 제20권5호
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• pp.755-761
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• 2006

Recently, there is growing interest in ultraviolet (UV) irradiation as a disinfection technic in drinking water production due to its effectiveness to inactivate microorganisms such as Crytosporidium parvum without forming disinfection byproducts. However, UV disinfection is known for its drawback such as photoreactivation. Despite many works concerning the photoreactivation, most of works were focused on indicator or non pathogenic microorganisms. The objective of this study is to examine the photoreactivation of Pseudomonas aeruginosa which is an opportunistic pathogen as UV radiation by LP and MP UV lamp was applied. The result showed that P. aeruginosa had high photo repair efficiency regardless of the type of UV irradiation. Both of the effective log repair values of LP and MP UV irradiation were found approximately 2.6 log. In addition, photo repaired P. aeruginosa was not significantly different in forming biofilm in comparison with non treated P. aeruginosa.

• 대한화장품학회지
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• 제40권3호
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• pp.307-311
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• 2014

2,3,5-Triphenyltetrazolium chloride (TTC)는 산화환원지시약으로 미생물의 증식에 의한 산소 소비를 쉽게 확인할 수 있다. 용해 후 무색의 형태를 띠고 있으나 생리활성이 있는 조직에서는 탈수소 효소(dehydrogenases)에 의해 환원되어 빨간색의 불용성 1,3,5,-triphenylformazan (TPF)가 된다. 본 연구에서는 병원성 미생물(Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecium, Candida albicans)에 TTC 지시약을 활용하여 미생물 성장시험에 대해 확인하였다. 시험 균주에 TTC를 첨가하여 확인한 결과, 모두 탈수소효소 반응으로 인한 TPF 형성으로 붉은색 콜로니를 관찰하였다. 이후 TTC 0.04% 이상의 농도 및 12 h 이상 배양조건으로 최적화 실험 후 균주별 CFU 값을 통해 TPF 발현능을 확인하였다. 결국 TTC가 병원성 세균 및 효모균 성장에 큰 영향을 끼치지 않으며 배양 시 세균의 경우 12 h, 효모균의 경우 48 h 이후부터 확인이 가능하였다. 이러한 결과들로부터 TTC를 활용한 미생물 성장 확인 시험법이 더 신속 정확한 방법으로 화장품 연구에 활용 가능할 것으로 사료된다.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1337-1340
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• 2008

The objective of this study was to evaluate the microbial safety of raw beef used to produce Korean beef jerky, The raw beef samples harbored large populations of microorganisms. In particular, psychrophilic bacteria were found to be most numerous ($9.2{\times}10^3-1.0{\times}10^5\;CFU/g$) in the samples. Mesophilic bacteria and anaerobic bacteria were present in average numbers ($10^3-10^5\;CFU/g$). Spore-forming bacteria and coliforms were not detected below detection limit. Yeast and molds were detected at $2.2{\times}10^1-7.8{\times}10^2\;CFU/g$ in the raw beef. Ten samples of raw beef were analyzed for the presence of pathogenic bacteria. Bacillus cereus was isolated from sample B, G, and H. The B. cereus isolates from raw beef samples were identified with 99.8% agreement according to the API CHB 50 kit.

• 상하수도학회지
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• 제30권3호
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• pp.285-291
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• 2016

There has been an accelerating increase in water reuse due to growing world population, rapid urbanization, and increasing scarcity of water resources. However, it is well recognized that water reuse practice is associated with many human health and ecological risks due to numerous chemicals and pathogenic microorganisms. Especially, the potential transmission of infectious disease by hundreds of pathogenic viruses in wastewater is one of the most serious human health risks associated with water reuse. In this study, we determined the response of different bacteriophages representing various bacteriophage groups to chlorination in real wastewater in order to identify a more reliable bacteriophage indicator system for chlorination in wastewater. Different bacteriophages were spiked into secondary effluents from wastewater plants from three different geographic areas, and then subjected to various doses of free chlorine and contact time at $5^{\circ}C$ in a bench-scale batch disinfection system. The inactivation of ${\phi}X174$ was relatively rapid and reached ~4 log10 with a CT value of 5 mg/L*min. On the other hand, the inactivation of bacteriophage PRD1 and MS2 were much slower than the one for ${\phi}X174$ and only ~1 log10 inactivation was achieved by a CT value of 10 mg/L*min. Overall, the results of this study suggest that bacteriophage both MS2 and PRD1 could be a reliable indicator for human pathogenic viruses for chlorination in wastewater treatment processes and water reuse practice.

• 대한환경공학회지
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• 제32권11호
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• pp.1063-1068
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• 2010

본 연구는 유효한 분변오염의 지표 미생물로서 제안되고 있는 E.coli와, 병원성 바이러스에 대한 지표 미생물로 추천되는 $Q{\ss}$ 파지의 UV 및 UV/$H_2O_2$에 대한 내성을 비교하였다. 이 결과에 의거, 병원성 바이러스 관리를 위한 E.coli 규제의 유효성을 고찰하였다. 또한, 병원성 바이러스에 대한 대체 지표 미생물로써, $Q{\ss}$ 파지, T4 및 lambda 파지의 실제 하수 2차 처리 수중에서의 UV 불활성화를 비교하였다. 실험결과, $Q{\ss}$ 파지와 E.coli는 UV에 대해 거의 동등한 내성을 보였으나, UV/$H_2O_2$ 공정에 대해서는 E.coli보다 $Q{\ss}$ 파지가 더 높은 내성을 보였다. 이로부터, $Q{\ss}$ 파지가 모든 병원성 바이러스의 UV 또는 UV/$H_2O_2$에 대한 내성을 대표한다고 할 수는 없을지라도, 지표 미생물로써 E.coli의 불활성화 효과에만 의존하는 것은, 소독공정에 따라서는 바이러스류에 대해 충분한 소독효과를 얻지 못할 수도 있음을 알 수 있었다. 한편, T4 및 lambda 등 DNA 파지와 불활성화를 비교하였을 경우, $Q{\ss}$ 파지가 UV에 대해 더 낮은 내성을 보였다. 따라서, 불활성화에 대한 지표 바이러스로써 $Q{\ss}$ 파지의 이용은 낮은 UV 조사량의 도입에 의해 결과적으로 불충분한 소독효과를 초래할 수도 있을 것 같다. 이 결과는, 병원성 바이러스류에 대해 보다 충분한 불활성화를 달성하기 위해서는 RNA 파지인 $Q{\ss}$보다 T4 및 lambda 등 DNA 파지가 지표 바이러스로써 보다 유효할 수 있음을 보여준다.

• Journal of Animal Science and Technology
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• 제62권5호
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• pp.682-691
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• 2020

Careful cleaning and disinfection of pigpens is essential to prevent disease spread and avoid the resultant economic losses. Hygiene in pigpens is generally evaluated by visual monitoring supplemented with bacteriological monitoring, which includes counting the total aerobic bacteria (TAB) and/or fecal indicator bacteria (FIB). However, these methods present drawbacks such as time and labor requirements. As adenosine triphosphate (ATP) is ubiquitous in all living organisms including microorganisms, this study aimed to directly compare the results of microbial assessment and ATP quantification, and to suggest possible detailed application methods of the ATP test for hygiene evaluation in pigpens of a farrowing unit. Before and after standard cleaning procedures, samples were collected from the floor corner, floor center, and feeding trough of four pigpens at different time points. No FIB were detected and both the TAB and ATP levels were significantly decreased in the floor center area after cleaning. FIB were continuously detected after cleaning and disinfection of the floor corners, and there was no significant ATP level reduction. The feeding trough did not show any significant difference in these values before and after cleaning, indicating insufficient cleaning of this area. The levels of TAB and ATP after cleaning were significantly correlated and the average ATP value was significantly lower in the absence of FIB than in their presence. In the absence of standard references, a more thorough hygiene management could be achieved evenly by supplementing cleaning or disinfection based on the lowest ATP results obtained at the cleanest test site, which in the present study was the floor center. Overall, these results indicate that the on-farm ATP test can be used to determine the cleanliness status, in addition to visual inspection, as an alternative to laboratory culture-based testing for the presence of microorganisms.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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• pp.53-60
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• 2000

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer, which has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by the API test and some characteristics. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the non-pathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by Lactococcus lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against non-pathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely disappeared by protease XIV or ${\alpha}$-chymotrypsin. The inhibitory activities of lacticin BH5 were detected during treatments up to 100$^{\circ}C$ for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. The cell concentration and bacteriocin production in strain BH5 were maximum when grown at 30$^{\circ}C$ in a modified MRS medium supplemented with 0.5% tryptone, 1.0% yeast extract, and 0.5% beef extract as nitrogen sources. It demonstrated a typical bactericidal mode of inhibition against Micrococcus flavus ATCC 10240. Lacticin BH5 was purified through ammonium sulfate precipitation, ethanol precipitation, and CM-Sepharose column chromatography. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3.7 kDa, by the direct detection of bactericidal activity after SDS-PAGE. Mutant strain NO141 which was isolated by nitrosoguanidine mutagenesis produced about 4 fold more bacteriocin than the wild type.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.379-383
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• 1988

활성슬러지법에 의한 벤젠폐수 처리실험을 통하여 활성슬러지의 벤젠처리중에 실제 그에 관여하는 세균을 분리 동정하였다. 반응조에서 분리한 세균은 6종으로, Pseudomonas fluorescens, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii와 Klebsiella pneumoniae로 동정되었다. 벤젠 분해능을 측정한 결과는 P. fluorescenss가 55%를 18시간만에 처리했고, E. cloacae는 24%, K. oxytoca 는 32%, E. agglomerans는 41%의 분해능을 보였다. P. fluorescens의 증식 최적조건은 온도 25-31$^{\circ}C$와 pH 7.0으로 확인되었다. P. fluorescens가 우점종일때 나타나는 지로생물은 원생동물인 Aspidisca sp.였다. 벤젠 농도가 387mg/$\ell$일 때에는 Aspidisca sp.와 Litonotus sp.가 증식을 최대로 하였고, 벤젠 농도가 1,600mg/$\ell$에서는 Litonotus sp.와 Vorticella sp.는 거의 성장하지 않았다. Glucose 배지에서는 모두 성장율이 높았다.

• 한국환경보건학회지
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• 제39권3호
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• pp.279-288
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• 2013

Objectives: Effectiveness and conditions of vapor-phase hydrogen peroxide (VPHP) system on decontamination of Geobacillus stearothermophilus(GS) spores, Escherichia coli (E.coli) and Enterobacteria phage felix01 (felix01) were determined. Methods: The VPHP system was designed to vaporize 35% (w/w) solution of hydrogen peroxide, continuously to inject and withdraw VPHP. The system and VHP 1000ED (Steris) were operated such that dehumidification and conditioning were initiated without samples in the chamber. Then the samples were loaded into and removed. Coupons (glass, anodizing, silicon, viton) with GS spores ($1{\times}10^6$ colony forming unit/mL [CFU/mL]), E.coli ($1{\times}10^7$ CFU/mL) and felix01 ($1{\times}10^7$ plaque forming unit/mL[PFU/mL]), and Biological Indicator (BI) with GS spores ($1{\times}10^6$ CFU/mL) on stainless steel coupons were used. The tested samples were sonicated and vortexed, and then were plated for enumeration, followed by incubation at $55^{\circ}C$, 24 hr for GS spores, and at $37^{\circ}C$, 24 hr for E.coli and felix01. BI analysis in broth culture was only qualitative. Results: The efficacy of the VPHP system on decontamination was almost equivalent to that of VHP 1000ED. The conditions for complete decontamination with the VPHP system was as follows: concentration; 700~450 ppm, relative humidity; approximately 55%, and temperature; $34{\sim}32^{\circ}C$. When comparing the decontamination efficiency among different kinds of coupons, glass was the most effective, however, all kinds of coupons were decontaminated completely after 60 min exposure in both systems. Conclusion: The VPHP system can be recommended as an alternative system for traditional system using ethylene oxide, formaldehyde or chlorine dioxide.

• 한국식품위생안전성학회지
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• 제33권5호
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• pp.399-403
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• 2018

본 연구에서는 양봉농가에서 대량 생산이 가능하고 영양이 풍부한 꿀벌 수벌번데기를 새로운 식품원료로 사용하기 위하여 유해 미생물과 곰팡이독소에 대한 안전성 시험을 수행하였다. 검사 시료는 국내 3지역의 양봉농가에서 직접 생산한 수벌번데기를 채취 후 곧바로 냉동 운반하여 동결건조하여 사용하였다. 식품공전 시험법에 따라 대장균군(Coliforms), 살모넬라(Salmonella spp.), 황색포도상구균(Staphylococcus aureus) 및 장출혈성대장균(Enterohemorrhage Escherichia coli)에 대한 검출 여부를 조사한 결과 280개의 벌통에서 채취한 수벌번데기 전부에서 전혀 검출되지 않았다. 또한 곰팡이 독소인 아플라톡신 $B_1$(aflatoxin), 오크라톡신 A (ochratoxin), 데옥시니발레놀(deoxynivalenol) 그리고 제랄레논(zearalenone)이 수벌번데기에서 전혀 검출되지 않았다. 따라서 벌통 내 소비에서 채취하여 곧 바로 냉동보관 한 수벌번데기는 유해 미생물과 곰팡이 독소로부터 안전한 것으로 확인되어 식품원료로 사용이 가능할 것으로 사료된다.