Bee-vectoring 기술은 벌이 작물에서 방화활동을 하는 동안 미생물제제를 식물체의 꽃이나 잎 등에 전파함으로써 병해충 방제를 가능케 하는 새로운 방제기술로 매개곤충, 미생물제제, 분배장치가 중요한 기술요소가 된다. 국내에서는 박 등(2009)에 의해 소개되었고, 지난 몇 년간의 연구에서 벌의 활동량, 제제 매개량을 높일 수 있는 분배 장치 등의 개발이 이루어져 왔다. 그러나, 수정벌이 안전하게 매개할 수 있는 미생물제제의 선발은 아직까지 이루어지지 않았다. 본 연구에서는 상업화된 미생물제제 제품중에서 이용 가능한 미생물제제를 선발하고자, 소형 케이지내에 농과원에서 개발한 분배장치를 뒤영벌 벌통에 연결하고, 벌이 분배장치를 통해 미생물제제를 묻혀나갈 때 벌에 묻혀나가는 양, 소형케이지내 벌의 활동성, 벌에 대한 안전성 등을 측정하였다. 벌의 사망률이 낮고, 벌의 활동에 부정적인 영향을 주지 않는 제제는 Bacillus thuringiensis kurstaki, Bacillus subtilis QST713, Bacillus subtilis Y1336, Simplicillium lamelicola BCP 였다. 또한 Bacillus subtilis QST713을 농가포장에서 검정한 결과, 소형케이지 시험과 일치되는 결과를 얻어 케이지시험이 미생물제제를 선발하는데 유용하다는 것을 확인할 수 있었다.
곰팡이, 세균, 바이러스 등 곤충병원균을 이용한 해충방제는 국민들의 안전농산물에 대한 요구의 증가와 함께 그 이용에 대한 관심이 증가하고 있다. 미생물 살충제는 살아있는 균을 이용하여 해충을 방제하는 수단으로 제한된 기주 종에 특이적으로 작용하여 천적 등 비표적 생물에 비교적 안전하며 환경오염 등이 없는 장점을 가지고 있다. 그러나, 미생물 살충제는 대상 해충에만 특이적으로 작용하여 방제가능 기주범위가 제한적이거나 동일 종 내에서도 발육단계별 살충율이 달라 최대 방제 효과를 얻을 수 있는 기간이 제한적인 단점을 가지고 있다. 또한 온도, 습도, 자외선 등 환경 조건에 영향을 받아 방제 효과가 불균일하고, 충분한 방제 효과를 얻는 데 소요되는 기간이 화학 농약에 비해 길어 실제 방제 현장에서 사용 증가가 더딘 실정이다. 이러한 단점을 극복하고 미생물 살충제의 사용을 증대시키기 위해서는 병원성이 높은 균을 선발하여 효과적인 발육단계, 기주범위, 사용가능 온・습도 범위, 선발 균의 적정 살포 농도, 살포 간격 등에 대한 연구와 효율적인 방제 모델 작성이 필요하다. 또한 동일 작물에서 사용되는 타 방제 수단과의 상호작용 (예, 천적에 미치는 영향, 살균, 살충제가 균에 미치는 영향, 화학농약과의 적정 처리 간격)에 대한 연구도 필요하다. 또한 곤충병원성 곰팡이 중에는 식물병원균의 방제 가능성이 보고된 균주도 있다. 이러한 병해충 동시방제 가능 균이나 수종의 해충 방제가 가능한 균주를 선발, 상용화 한다면, 곤충병원균을 이용한 미생물 살충제의 이용이 증가함과 동시에 이에 대한 연구도 보다 활발해 질 것으로 기대된다.
This study was conducted to investigate the microbiological contamination levels in rice cakes and rice flour due to climate change in three areas classified to their temperature and precipitation. We investigated the contamination levels of total aerobic bacteria, coliforms, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Clostridium perfringens of rice flour and 3 rice cakes such as Garaetteok, Sirutteok and Gyeongdan. Contamination levels of total aerobic bacteria in rice flour were 4.9 log CFU/g. In a total of 70 rice flour, yeasts & molds and coliforms were detected in 42 and 52 samples at the levels of 43 CFU/g and 1.29 log CFU/g, respectively. S. aureus were detected in only 1 rice flour (1.66 log CFU/g) out of 70. In an investigation of contamination levels in rice cakes, the population of total aerobic bacteria were highest in Gyeongdan (5.18 log CFU/g) and coliforms were highest in Gareattock (2.93 log CFU/g). There was no detection of E. coli and B. cereus except for only 1 Gareattock (1.20 log CFU/g). There were no differences of contamination levels among the three areas. If constant monitoring of rice cakes and rice flour is conducted on the basis of this study, it is expected to be able to analyze the change of contamination levels in rice cakes and rice flour due to climate change.
The purpose of this study was to analyze microbiological hazards for plants, cultivation environments and personal hygiene of perilla leaf farms at the harvesting stage. Samples were collected from three perilla leaf farms(A, B, C) located in Gyeongnam, Korea and tested for sanitary indications, fungi and pathogenic bacteria( Escherichia coli O157:H7, Listeria monocytogens, Salmonella spp., Staphylococcus aureus and Bacillus cereus). As a result, total bacteria and coliform in perilla leaf were detected at the levels of 4.4~5.2 and 3.4~4.3 log CFU/g, respectively, but E. coli was not detected in all samples. Among the pathogenic bacteria, B. cereus(perilla leaf: 2.0~2.4 log CFU/g, stem: 1.4~2.1 log CFU/g, water: 0.7 log CFU/ml, soil: 4.2~5.0 log CFU/g, hands: 3.0 log CFU/ hand, gloves: 2.1~2.4 log CFU/100 cm2, glothes: 1.5~2.8 log CFU/100 cm2) and S. aureus(3.4 log CFU/hand) were detected in all samples and worker's hand from farm A, respectively. However, other pathogenic bacteria were not detected. This study demonstrates that perilla leaf at the harvesting stage was significantly contaminated with microbial hazards.
The objective of this study was to investigate and evaluate microbial contamination levels of leafy greens (perilla leaf and lettuce) and its distributing conditions at different seasons (Feb, May, Aug, and Nov of the year 2011) in order to provide insight into any potential health hazards associated with consumption of these commodities. Leafy greens were collected from a farm located in Geumsan, Chungnam and wholesale markets (WM) and traditional markets (TM) located in Suwon. At the same time, temperature and relative humidity fluctuations experienced by the leafy greens during distribution from the farm to the distribution center were measured by a data logger. The contamination levels of perilla leaf and lettuce were determined by analyzing total plate count. Coliform groups, Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were determined. The contamination levels of total aerobic bacteria, coliform groups and B. cereus in both vegetables sampled during May and August found to be higher than those sampled during February and November. E. coli O157:H7, Salmonella spp., L. monocytogenes were not detected in the vegetables analyzed in this study. There were no significant trends between samples at WM and TM in the contamination levels. Relative humidity of vegetables distributed from the farm to the distribution center showed over 90% during distribution regardless of measured seasons. In the case of background microflora on leafy greens, the density was significantly increased at 20, 30 and 37oC during storage of 24h. E. coli O157:H7 and B. cereus inoculated on the leaves also showed similar increases in the storage tests. The microbial contamination levels determined in this study may be used as the fundamental data for microbial risk assessment.
The transmission of the world Installed in an Office occurs through the air. Preventing that transmission, especially in indoor environments like those in airplanes, schools and offices, is a major public health concern. in this study the real situation of lab which is consist of dilution, Ultraviolet-C based air sterilization system. This model include indoor microbe transport which is generated human source. a computer simulation was performed to determine if such simulation can be used effectively to predict the more accurate, but difficult to perform, actual physical experiment. Result show that CFD can be modeled microbe transport effectively and it can be visualized microbe transport separation from flow streamline. also it make a good prediction of microbe transport.
In this study the real situation of apartment house in seoul is reproduced with multi-zone modeling program contam2.4. This model include immune building system(disinfection system) which is consist of dilution, Filter Technology and UVGI(ultra violet germicidal irrdiation). In this study experiments design method used for estimating interaction of HRV air change rate, UVGI air change rate and UVGI grade. Result show that HRV air change rate and UVGI air change rate is most influence factor for remove rate. also Interaction of HRV air change rate and UVGI air change rate is ost influence factor for remove rate.
iarrheal diseases constitute one of the major causes of morbidity and mortality in infants and young children globally. One of the main microorganisms causing diarrheal diseases is Campylobacter jejuni. For treatment of these diseases, Portulaca oleracea has been widely used as a folk remedy for a long time. This study was performed to investigate the antimicrobial activity of P. oleracea against gastroenteritis pathogens including C. jejuni. P. oleracea was extracted with petroleum ether, chloroform, ethylacetate, methanol, and hot water. The antimicrobial activity of the P. oleracea extracts was determined using the paper disc method, minimum inhibitory concentration, and the liquid culture method. The 10 ㎎/㎖ ethylacetate extract showed the strongest antimicrobial activity against Salmonella typhimurium, Salmonella enteriditis, and Shigella spp.. The hot water extract from P. oleracea showed the highest anti-microbial activity against C. jejuni at 10~20 ㎎/㎖. The hot water extract of P. oleracea retarded the growth of C. jejuni for 36 hr at 42℃.
Microbial parameters of indoor air containing systematic, random, and accidental error were analyzed statistically by the water quality control guidelines to suggest a guideline of indoor air. Samples were collected from 20 subway stations of Seoul Metropolitan City. Systematic errors resulted from sampling devices were checked and removed by using same devices and flow rate check. Another source of systematic error resulted from different testing personals were assessed and qualified by proficiency test. Increase of replicate sample numbers could minimize random errors and use of geometric mean instead of arithmetic mean gave more statically reliable representative values for microbial parameters. Considerations for the culture media, colony counting results with incubation time, and statement of supplemented statistical data were also suggested.
This study was conducted to evaluate microbial contamination levels of Korea traditional rice cakes such as Sirutteok, Garaetteok and Gyeongdan in the manufacturing process and environment. The microbial contamination levels such as total aerobic bacteria, fungi, coliforms, Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens of rice cake products were analyzed. The contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in raw materials were in the range of 2.4~4.5, ND~1.9, 1.2~2.1 and 1.0~2.1 log CFU/g, respectively. The microbial contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in manufacturing process of rice cakes were increased in the soaking and grinding steps and were decreased in steaming step. E. coli, S. aureus and C. perfringens were not detected in any manufacturing process and environment. The microbial contamination levels of raw materials and final products of rice cake were suitable for microbial safety standard in Korea. However, the manufacturing environment such as equipments and employee's sanitation were in trouble for microbial safety. The results of this study suggest that safety education for personal hygiene and safety management in processing environment are continuously required to assure safety in working environment and employee's individual hygiene.
This study was conducted to assess the levels of microbiological hazards of preprocessed Namuls, which were served at the school foodservice. 19 preprocessed ground or root vegetables were collected from 21 schools in May to June of 2011. Heavy contamination of aerobic plate counts (from 3.39 to 8.42 logCFU/g) and total coliform groups (from 3.16 to 7.84 logCFU/g), enterobacteriaceaes (from 2.53 to 7.55 logCFU/g) were detected in preprocessed Namuls. In addition, the detection rates of Escherichia coli, Staphylococcus aureus and Bacillus cereus (emetic form) were 4.3%, 11.7% and 2.1%, respectively. In addition, sanitary indicative bacterium at preprocessing steps of root vegetables (lotus root, burdock root, bellflower root) and blanched Namuls (bracken, sweet potato vine, chinamul) were analyzed. Aerobic plate counts, coliform groups, and enterobacteriaceaes were not effectively removed during preprocessing including washing and soaking steps. In the case of blanched Namuls (bracken, sweet potato vine, chinamul), contamination levels increased more after drying process and no significant reduction effect on the levels of microbial contamination was observed during preprocessing steps. Thus, effect of preprocessing steps on the microbiological hazards in Namuls must be reevaluated to improve the microbiological quality of preprocessed Namuls at the school foodservice and retail markets.
본 연구는 음식점을 대상으로 QMRA의 개념을 적용한 HACCP 전산프로그램을 개발하고 이를 음식점내의 HACCP에 준한 위생관리 수단으로 이용, 최종 음식의 미생물 오염 수준을 예측하여 배식되는 음식의 미생물적 안전성을 확보하여 식중독 사고를 미연에 방지할 수 있는 방법을 모색하였다. QMRA-HACCP 전산프로그램의 개발을 위하여 메뉴를 그룹화하고, 위해분석, 중요관리점의 설정, 관리기준 설정, 모니터링 방법의 설정, 수정조치의 확립 및 기록유지시스템의 확립과 같은 HACCP의 기본적인 7원칙에 의거하여 HACCP 플랜을 개발하였다. 본 QMRA-HACCP 전산프로그램은 일일점검 작업 DB, 정기정검 DB, DAQ DB 및 Rule DB 등 데이터베이스 파일을 보유하여 최종 음식의 미생물 오염 수준을 예측할 수 있으며, 데이터베이스 파일은 수정·보완할 수 있다. 또한 MS Excel의 DB 관리 능력과 MS VBA(Visual Basic Application)을 이용한 프로그램으로 Window에서 사용자가 쉽고 편리하게 이용할 수 있도록 고안되었으며, 가시적인 관리가 수월하다. 모델 음식점을 통하여 선정된 9가지 메뉴에 대하여 개발된 QMRAHACCP 전산프로그램을 이용, 최종 제품의 미생물 오염 수준을 추정하였으며, 추정된 결과를 바탕으로 민감도 분석과 시나리오 분석을 통하여 중요관리점 및 CL을 선정하였다. 본 연구를 통하여 제시된 Generic HACCP 모델은 일반적인 음식점에서 사용할 수 있도록 비교적 간단하게 계획되어 있으므로 실제 음식점에서 일어날 수 있는 모든 위해를 통제할 수는 없다. 그러므로 각 음식점의 작업 현실에 맞도록 재구성하여 적용하는 것이 바람직하다고 사료된다. 또한 개발된 QMRA-HACCP 전산 프로그램을 다양한 음식에 적용하여 그 효과를 검증하는 후속 연구 및 표준레시피 데이터 화일의 지속적인 보완이 필요하겠으며, 다른 음식점에서 QMRA-HACCP 전산프로그램을 이용하여 위생관리를 수행하고, 동시에 미생물적 평가를 병행하여 각 결과간의 상관성을 규명하여 개발된 프로그램의 효율성과 정확성을 재확인하는 연구가 실행되어야 할 것이다.
고춧가루의 품질 변화를 낮추면서 살균하는 기술을 개발하고자 감압방전플라즈마(LPDP)를 이용한 비가열살균을 시도하였고 LPDP 처리에 의한 품질변화를 조사하였다. 시중 판매 고춧가루의 오염도는 세균 7.33×104-1.07×107 CFU/g, 진균류 3.47×104-3.16×106 CFU/g의 범위를 보여 상당한 수준으로 오염된 식품으로 확인되었다. 고춧가루의 LPDP 살균 패턴은 2단계 1차 반응으로 나타났으며, 출력에 따라 살균속도상수가 증가하였다. 또한 입자가 가늘수록 살균효과가 증가하였으며, 미생물 종류별로는 세균에 비하여 진균에 대한 살균효과가 크게 나타났다. 과도한 LPDP 처리는 고춧가루의 탈색과 capsaicinoids 함량의 감소를 유발하였다. LPDP 처리 고춧가루를 사용하여 조리한 무채의 관능검사 결과 색과 맛은 5분 처리까지는 무처리구와 차이가 없었으나 10분 처리 시에는 유의하게 낮은 점수를 보였다. 반면 향과 기호도에서는 처리구와 무처리구 간에 유의차를 보이지 않아 5분 이하로 LPDP 처리 시 관능특성을 유지하면서 약 1.5 log 정도의 미생물 저감화가 가능하였다.
This study was investigated to determine the contamination levels of total aerobic bacteria, coliform group, E. coli and food-borne pathogens of side dishes from 2 traditional markets (100 samples) and 2 super markets (100 samples) located on Ulsan. The levels (range) of total aerobic bacteria was 4.75 log CFU/g (1.60~6.92 log CFU/g) in traditional market and 4.62 log CFU/g (2.00~6.46 log CFU/g) in super market, respectively. Coliform was detected in 64 and 66 samples sold at traditional markets and super markets, respectively. E, coli was detected in 4 and 6 samples sold at traditional markets and super markets, respectively. The food-borne pathogens, namely Bacillus cereus and Listeria monocytogenes were detected in 1 sample sold at traditional markets, respectively, and Bacillus cereus was detected in 4 samples sold at super markets. However, other pathogens such as Salmonella spp., Shigella spp., Vibrio parahaemolyticus, Yersinia enterocolitica, Clostridium perfringens, Camphylobacter jejuni and Pathogenic E. coli were not detected. The Saengchae and Seasoned Jeotgal were relatively vulnerable compared to the others in the food-borne pathogens.
This study was conducted to evaluate the microbiological hazard on nursery school children's hands and to investigate the reduction effect of hand washing education. A total of 59 nursery school children's hands were tested. The average number of total aerobic bacteria was 3.72 ± 0.38 log CFU/hand. Five children's hands(2 male and 3 female) were positive(14.3%) for the coliform bacteria. These results showed that hand washing education are required repetitively. Among the pathogenic bacteria tested in this study, Staphylococcus aureus and Bacillus cereus were detected in 9(25.7%) and 16(45.7%) out of 35 their hands, respectively. Twelve out of sixteen B. cereus isolates(70.0%) produced enterotoxin. The results indicate that the hand hygiene of nursery school children needs to be improved. Comparing before and after hand washing in educated and non-educated group, the reduction effect of total aerobic bacteria on their hands was 0.42 and 0.60 log CFU/hand, respectively. The educated group showed 0.18 log CFU/hand higher reduction effect than non-educated group but microorganism did not eliminate perfectly. From the results, using a hand sanitizer after washing with soap and the continuous hand washing education are required to control the contaminated bacteria on nursery school children's hands.