• 한국환경보건학회지
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• 제40권2호
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• 한국산림과학회지
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• 제84권2호
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• pp.178-185
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• 1995

여천공단의 대기오염이 산림생태계에 미치는 영향을 파악하기 위하여 공단의 남단에 위치한 남해화학주변과 그 지역에서 2km, 4km, 6km, 8km 및 10km 떨어진 지점을 선정하여 산림토양의 화학적 특성, 탈질균 및 황산환원균 동태와 지의류 출현도를 비교하였다. 여천공단 주변지역의 토양은 적황색 산림토양군(R Y)에 속하는 토양이었으나 같은 산림토양군에 속하는 토양에 비해 pH가 매우 낮았다. 산림토양의 pH가 낮음으로 인해 C/N비가 15~25의 범주에 있음에도 불구하고 유기물의 분해 등 무기화에 관여하는 미생물의 활력이 낮아서 유기물함량이나 전질소함량은 상대적으로 높았다. 공단 인접지역에서 4km 지점에 이르는 곳까지의 토양 화학특성이 6km 이후 지역에 비해 대기오염 피해도가 심하게 나타났으나 탈질균 및 황산환원균의 분포량 차이에 따른 피해도 구분은 어려웠다. 한편, 지의류는 산림토양에 반영된 대기오염도의 차이에 비해 확연한 결과를 나타냈으며, 특히 엽상지의류는 바위에 붙어 사는 지의류에 비해서 더 민감한 반응을 나타냄을 확인할 수 있었다.

• 한국토양비료학회지
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• 제30권2호
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• pp.200-207
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• 1997

우리 나라 논 토양 환경의 생물학적 특성을 파악하기 위하여 전국 13개 농업기후지대별 63개 지점의 이앙전 무담수 논 토양의 표토를 채취하여 주요 토양 미생물의 밀도 및 다양성을 조사하였다. 농업기후지대별 전국 평균치 이상의 미생물 종류는 북부지방 보다는 남부지방일 수록 많았으며, 검정된 미생물중 지역간 차가 가장 큰 균은 형광성 Pseudomonas 속이었다. 지형간 미생물 밀도는 호기성 세균, 형광성 Pseudomonas 속과 Azotobacter 속등이 하해혼성지에서, 토성간에는 사상균이 식토에서, Bacillus 속, Azotobacter 속 그리고 탈질균은 식양토에서 유의적으로 가장 높았다. 한편 Azotobacter 속과 암모니아 산화세균의 밀도는 토양 pH가 높아 질수록 증가하였다. Bacillus 속, 형광성 Pseudomonas 속, Azotobacter속, 탈질균, 암모니아 산화균, 아질산산화균, 방선균 및 사상균등을 요인으로 한 미생물 다양성 지수의 지역간 최소 값은 0.109, 최대 값은 0.661 이었다. 지형별 다양성 지수는 하해혼성지가 0.332, 홍적대지 0.335, 하성평탄지 0.432 그리고 곡간선상지 0.447이었으며, 토성별 다양성지수는 사질 0.443, 사양질 0.427, 미사식양질 0.414, 식양질 0.405 그리고 식질토양이 0.362로 사질토양일수록 증가하는 경향이었다.

• 한국식품위생안전성학회지
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• 제31권3호
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• pp.216-221
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• 2016

본 연구는 S. Typhimurium을 대상으로 paraformaldehyde 35%를 함유한 훈증소독제의 살균효과를 평가하기 위해 수행되었다. 예비 시험에서, S. Typhimurium의 현탁액 균수는 모두 $3.9{\times}10^8CFU/mL$이었으며, 훈증소독제에 노출시킨 모든 담체의 균수는 평판배지법과 여과법으로 배양한 시험균주 현탁액의 균수의 50%보다 많았다. 또한, 대조 담체로부터 회복된 S. Typhimurium 균수는 모두 $3.3{\times}10^6CFU/mL$이었다. 훈증소독제의 살균효과 시험에서는, 훈증 소독제를 처리한 담체의 S. Typhimurium의 감소 균수는 5.22 log CFU/mL로 나타났다. 이상의 결과로부터, paraformaldehyde를 주성분으로 하는 훈증소독제는 S. Typhimurium에 대해 효과적인 살균력을 갖는 것으로 확인되었으며, 병원성 세균에 오염된 식품재료 및 주방용품의 소독에 적용할 수 있을 것으로 사료된다.

• 한국환경보건학회지
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• 제40권6호
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• pp.469-476
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• 2014

Objectives: The purpose of this study was to identify the stains causing infections in dental clinics by analyzing bacterial contamination, as well as to suggest improvements for infection control in dental clinics. Methods: In this study, a questionnaire survey of 47 dental hospitals and clinics located in Gyeonggi-do and Incheon, South Korea was administered from June 2013 to September 2013 and used to investigate the practice rates of infection control by dental hygienists and to analyze the bacterial contamination levels in dental offices. Results: In the studied institutions, the bacterial contamination levels of water lines were $20.9{\times}10^3$ colony forming units (CFU)/mL for three-way syringes, $12.7{\times}10^3CFU/mL$ for high-speed handpieces and $9.8{\times}10^3CFU/mL$ for gargling water. The bacterial contamination levels of surfaces were $44.9{\times}10^3CFU/mL$ in cuspidors, higher than in unit chairs ($2.9{\times}10^3CFU/mL$) and light handles ($6.7{\times}10^3CFU/mL$). The mean bacterial cell count of water lines and surfaces was relatively high in all establishments founded 11 years ago or more, and the mean bacterial cell count of waterline handpieces was $6.27{\times}10^3CFU/mL$ in establishments founded between one and five years ago, $11.16{\times}10^3CFU/mL$ six to ten years ago and $20.04{\times}10^3CFU/mL$ 11 years ago or more, which suggests that earlier foundation is associated with higher bacterial contamination levels with a statistical difference (p<0.01). Similarly, the mean bacterial cell count of cuspidors using water from water lines was also $70.16{\times}10^3CFU/mL$ in at least 11-year-old establishments, statistically significantly higher among in one- to five-year-old ($4.61{\times}10^3CFU/mL$) and six- to ten-year-old clinics ($47.89{\times}10^3CFU/mL$) (p<0.05). Conclusion: This study may be utilized to improve the bacterial contamination levels in dental offices by controlling the characteristics and environmental factors of dental offices that affect the microbial contamination of waterlines and surfaces in such institutions.

• Asian-Australasian Journal of Animal Sciences
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• 제10권1호
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• pp.79-85
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• 1997

Cage layer waste and sudex grass were ensiled in the proportions of 0:100, 30:70, 40:60 and 50:50 wet basis, respectively. The influence of ensiling cage layer waste on Salmonellae, Shigella, Proteus, and total number of colony forming units (CFU) was investigated. The nutritive value of the silages was evaluated in a digestion trial. The experiment was conducted with 24 wethers allotted to four silages. Initial samples of cage layer waste showed $0.11{\times}10^6$ CFU and salmonellae, Shigella and Proteus were present. Ensiling was effective in complete elimination of all the pathogens. Dry matter, crude protein and ash contents were increased linearly (p < .01) with the increase of cage layer waste in the silages ($358g{\cdot}kg^{-1}$ to $484g{\cdot}kg^{-1}$; $76.3g{\cdot}kg^{-1}$ to $183.2g{\cdot}kg^{-1}$ and $38.5g{\cdot}kg^{-1}$ to $169.4g{\cdot}kg^{-1}$; DM basis, respectively). Water solubles carbohydrate values for silages were 38.3, 22.5, 20.1 and $20.0g{\cdot}kg^{-1}$ DM basis, respectively. Ensiling decreased the pH values for all the silages and the decrease was higher for sudex grass ensiled alone than grass ensiled with cage layer waste. Lactic acid concentration in silages increased linearly (p < .01) with the increase of cage layer waste. The apparent digestibilities of DM, OM and CP for the animals fed sudex grass silage alone were 496.0, 516.1, $496.7g{\cdot}kg^{-1}$ DM basis respectively. However, digestibilities of all the components were higher (p < 0.01) for the animals fed silages containing cage layer waste. Among waste containing diets, the digestibilities of all the components showed quadratic affect (p < 0.01), increased for silages containing 30 and 40% cage layer waste and decreased when the level of waste increased from 40 to 50%. The results indicated that cage layer waste can be used upto 40% in ruminant diet as a source of N without any adverse effect on the health of animals. Ensiling appeared to be feasible and effective method for eliminating the pathogen present in cage layer waste.

• 한국콘텐츠학회논문지
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• 제13권2호
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• pp.314-321
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• 2013

광역학 치료는 미생물의 감염을 포함한 다양한 질병을 위한 대안치료로 권장된다. 이 연구의 목적은 포도알균속에 대한 직접제작한 630 nm 발광다이오드와 포토프린을 사용하여 광역학 치료의 항균효과를 평가하고자 하였다. 포토프린을 이용한 광역학 치료는 황색포도알균과 표피포도알균에 대한 항균효과를 집락형성수 정량법과 세균 생육능은 유세포분석기를 이용하여 시험하였다. 황색포도알균과 표피포도알균의 집락형성수 결과는 포토프린 $50{\mu}g/m{\ell}$와 630 nm 발광다이오드로 에너지밀도 $18J/cm^2$ 조건으로 광역학 치료 적용 후 각각 평균 1 cfu/ml와 평균16 cfu/ml이다. 추가로 광역학 치료 후 황색포도알균과 표피포도 알균을 유세포분석기로 세포의 크기와 형광강도를 측정하였다. 황색포도알균과 표피포도알균의 세포크기는 광역학 치료 후 평균 8.96% 5.55%씩 각각 증가하였고, 세균의 죽은세포는 각각 39%와 61%로 증가하였다. 이 결과로 포토프린을 이용한 광역학 치료는 항균치료의 방법으로 효과적인 방법이 될 수 있음을 제의한다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권3호
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• pp.378-384
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• 2007

Three microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of whole-crop wheat, sorghum and maize silages. Wheat at the early dough stage, sorghum at the late milk stage and maize at the one-third milk line stage were harvested and ensiled in 1.5-l anaerobic jars untreated or after the following treatments: control (no additives); Lactobacillus plantarum (LP) at $1.0{\times}10^6$ colony-forming units (CFU)/g of fresh forage; L. buchneri (LB) at $1.0{\times}10^6$ CFU/g; Propionibacterium acidipropionici (PA) at $1.0{\times}10^6$ CFU/g; and a formic acid-based preservative (FAP) at 3 ml/kg of fresh forage weight. Three jars per treatment were sampled on d 90 after ensiling, for chemical and microbiological analysis. At the end of the ensiling period, 90 d, the silages were subjected to an aerobic stability test lasting 5 d. In this test, $CO_2$ produced during aerobic exposure was measured along with chemical and microbiological parameters which serve as spoilage indicators. The silages inoculated with LP had higher concentration of lactic acid compared with the controls and the other treated silages (p<0.05). The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages. The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages due to more $CO_2$ production (p<0.05) in these two groups and development of yeasts unlike the other groups. In the experiment, the silages treated with LB, PA and FAP were stable under aerobic conditions. However, the numbers of yeasts was higher in the LP-inoculated wheat, sorghum and maize silages compared with the LB, PA and FAP-treated silages. The LB, PA and FAP improved the aerobic stability of the silages by causing more extensive heterolactic fermentation that resulted in the silages with high levels of acetic and propionic acid. The use of LB, PA and FAP as silage additives can improve the aerobic stability of whole-crop wheat, sorghum and maize silages by inhibition of yeast activity.

• Asian-Australasian Journal of Animal Sciences
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• 제28권6호
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• pp.807-815
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• 2015

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

• Asian-Australasian Journal of Animal Sciences
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• 제17권3호
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• pp.401-409
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• 2004

Two experiments were conducted to evaluate the effects of a complex Lactobacilli preparation on performance, resistance to E. coli infection and gut microbial flora of weaning pigs. In exp. 1, twelve pigs (7.65$\pm$1.10 kg BW), weaned at 28 d, were randomly allotted into 2 groups and placed in individual metabolic cages. During the first 7 d, one group of pigs was provided ad libitum access to water containing $10^5$ colony forming units (CFU) Lactobacilli per ml and the control group was provided tap water. The Lactobacilli preparation included Lactobacillus gasseri, L. reuteri, L. acidophilus and L. fermentum, which were isolated from the gastrointestinal (GI) tract mucosa of weaning pigs. On d 8, 20 ml of $10^8$ CFU/ml E. coli solution (serovars K99, K88 and 987P at the ratio of 1:1:1) was orally administered to each pig. Diarrhea scores and diarrhea incidence were recorded from d 7 to 14. On d 14, pigs were euthanized and digesta and mucosa from the stomach, duodenum, jejunum, ileum, cecum and colon were sampled using aseptic technique to determine microflora by culturing bacteria in selective medium. The results showed that Lactobacilli treatment significantly decreased E. coli and aerobe counts (p<0.01) but increased Lactobacilli and anaerobe counts (p<0.01) in digesta and mucosa of most sections of the GI tract. A 66 and 69.1% decrease in diarrhea index and diarrhea incidence, respectively, was observed in the Lactobacilli treated group. In exp. 2, Thirty-six crossbred Duroc$\times$Landrace$\times$Yorkshire piglets, weaned at 28$\pm$2 days, were selected and randomly allocated into 2 groups. There were 18 piglets in each group, 3 piglets in one pen and 6 replicates in each treatment with 3 pens of barrow and 3 pens of female piglet in each treatment. Piglets had ad libitum access to feed and water. The initial body weight of piglet was 7.65$\pm$1.09 kg. Dietary treatments included a non-medicated basal diet with Lactobacilli ($10^5$ CFU/g diet) or carbadox (60 mg/kg) as control. On d 21, six pigs per group (one pig per pen) were euthanized. Ileal digesta was collected to determine apparent amino acid digestibility. Microflora content was determined similarly to exp.1. The results showed that Lactobacilli treatment significantly improved average daily feed intake (ADFI) of pigs compared to carbadox (p<0.05) during the first 2 wks after weaning and average daily gain (ADG) and ADFI increased significantly (p<0.05) from d 8 to 14. Nitrogen and total phosphorus digestibility also increased (p<0.05). Bacterial counts were similar to exp. 1. The results indicate that the complex Lactobacilli preparation improved performance for 2 wks after weaning, enhanced resistance to E. coli infection, and improved microbial balance in the GI tract.