This study was carried out to investigate the effect of chlorine water and plasma gas treatment on the quality and microbial control of Latuca indica L. baby Leaf during storage. Latuca indica L. baby leaves were harvested from a plant height of 10cm. They were sterilized with 100μL·L-1 chlorine water and plasma-gas (1, 3, and 6hours), and packaged with 1,300cc·m-2·day-1·atm-1 films and then stored at 8±1?and RH 85±5% for 25days. During storage, the fresh weight loss of all treatments were less than 1.0%, and the carbon dioxide and oxygen concentrations in packages were 6-8% and 16-17%, respectively for all treatments in the final storage day. The concentration of ethylene in the packages fluctuated between 1-3μL·L-1 during the storage and the highest concentration of ethylene was observed at 6 hours plasma treatment in the final storage day. The off-odor of all treatments were almost odorless, the treatments of chlorine water and 1 hour plasma maintained the marketable visual quality until the end of storage. Chlorophyll content and Hue angle value measured at the final storage day were similar to those measured before storage in chlorine water and 1 hour of plasma treatments. E. coli was not detected immediately after sterilization in all sterilization treatments. After 6 hours of plasma treatment, the total bacteria fungus counts were lower than the domestic microbial standard for agricultural product in all sterilization treatments. The total aerobic counts in the end storage day increased compared to before storage, whereas E. coli was not detected in all sterilization treatments. The sterilization effect against bacteria and fungi was the best in chlorine water treatment. Plasma treatment showed sterilization effects, but within a prolonged period of time. In addition, the sterilization effect decreased gradually. These results suggest that chlorine water and plasma treatment were effective in maintaining Latuca indica L. baby Leaf commerciality and controlling microorganisms during postharvest storage.

Thrips worms and root-knot nematodes occur in a variety of crops, and have shown a great deal of damage to farm income every year, and the damage is increasing every year. In order to solve these problems, a variety of biological materials are used in Korea to develop a control agent. However, there are very few products available that can satisfy the consumer's satisfactory control effect, efficacy, formulation stability and pesticide compatibility. In order to propose a biological control solution to these problems, this study was conducted to develop the optimal bioprocess technology and formulations suitable for the material by transferring the Aspergillus nigerF22 strain, which is effective for root-knot nematodes, at Chonnam National University. This study was conducted to investigate the efficacy of Aspergillus niger F22 20% suspension concentrate (Productname:NEMAFREE), which has excellent efficacy on root nematodes. The packing test result showed about 70-90% control effect. Soil fumigation and disinfection treatments after 4 days of planting were effective. In addition, we have developed a product to control the under powder pupa using Beauveria bassiana ERL836, an insect pathogenic microorganism, which has excellent control effect against resistant insect pupa. The main purpose of this study was to investigate the effect of insect pests on the under poor control of the pupa in the soil. In the pavement test, more than 70%(GR) formulation, which can be treated withch emical pesticides, and it is confirmed that synergy effect is in the control of Thrips worm.

Various arthropods have directly and indirectly threatened human life by transmitting human pathogens such as malaria and Zika virus as well as by damaging crops such as direct feeding and transmission of plant pathogens. According to WHO, vector-borne diseases account for over 17% of all infectious diseases and there are over 1 million deaths from the diseases such as malaria, dengue, etc., globally. About 13% of total crop production is destroyed by agricultural pests during crop production and storage. To control medical or agricultural pests chemical pesticides have been used, but recently because of concerns about environmental pollution and human health the demands for eco-friendly control method are increasing. Insect pathogens are good alternative candidates instead of chemicals. Over 50 entomopathogens including viruses, bacteria, fungi and nematodes are now commercially used as microbial pesticides. Entomopathogenic fungi have also been evaluated as control agents for a diverse insect pests such as aphid, moth, thrip, whitefly, mosquitoes, tick, etc. We will discuss a development of microbial pesticides using, especially, entomopathogenic fungi to control noxious arthropods to agricultural crops and human.

Insect pests have been a serious problem over many years and remain a major threat for food production. Although chemical pesticides are major pest control strategies, use of microorganisms such as entomopathogenic bacteria, fungi, viruses and nematodes have continuously increase last few decades to minimize the use of agrichemicals. According to BBC research, the global biocontrol market was about $2.1 billion in 2011, and this is expected to rise $3 ~ 4 billion by 2017. Over 50 entomopathogens are commercially produced and used augmentatively as microbial pesticides. About 175 biopesticide active ingredients and 700 products have been registered worldwide. Bacillus thuringiensis (Bt), Beauveria bassiana, Metarhizium spp., nuclear polyhedrosis virus and Steinernema spp. are the most popular control agents used in plant protection. Among the microbial control agents Bt products have more than 50% of market share. In Korea, only 13 environmentally-friendly crop protectants were registered for insect pest control in 2015. Market share is very low and has grown slowly. We will discuss how we can expand the market with our techniques.

Bacillus thuringiensis (Bt) is a Gram-positive and soil-dwelling bacterium and well known for its ability to produce insecticidal parasporal crystalline protein inclusions, which have attracted worldwide interest for effective pest management. A diseased silkworm by Bt was first discovered by Japanese scientist Ishiwata Shigetane in 1901, and in 10 years, it was re-discovered in Germany by Ernst Berliner, who isolated it as the cause of a disease called Schlaffsucht in flour moth caterpillars. The first commercial product, Bt. kurstaki HD-1 was released to a market in France in 1938. Optimization of mass production for crystal production and cost down enabled the industrialization to be successful, and now many products, such as WP, EC, SC and tablets are used worldwide. In 1976 Robert A. Zakharyan found that plasmids in Bt are involved in the production of crystal proteins and endospores. Pore formation model and signal transduction model were revealed to explain the mode of action of Bt. Works on Bt resistance included a group of receptors of crystal proteins, such as cadherin, APN and ALP. In 1996, a Bt cry gene was integrated to cotton, which successfully reached markets. AtMT technology was used to generate Bt crops. Now the area planted worldwide to genetically engineered Bt crops increased to 66 million hectares. Refuge may be particularly important in slowing the spread of insects resistant to the Bt insecticides. Researchers are trying to increase the insecticidal efficacy of integrated Bt crystal proteins using recent biotechnology.

Beet armyworm, Spodoptera exigua are difficult to control using chemical insecticides because of the development of insecticide resistance. For eco-friendly beet armyworm managements, various control agents are required. Entomopathogenic fungus is one of promise control agents as an alternative to chemical control agent. We isolated entomopathogenic fungi from soil samples of suwon by insect-bait method using Galleria mellonella and conducted bioassay to larva of beet armyworm. As a result of bioassay isolate FG274, FG340, FG344 had high virulence as 100% against second instar larva of S. exigua. To identify the fungus isolates, their’s morphological characteristic was observed and ITS of 18srRNA was sequenced. ITS sequence of FT274, 340, 344 were highly matched (100%) to that of Beauveria bassiana, Paecilomyces fumosoroseus, Metarhizium anisopliae. To investigate the optimal concentration, three isolates were sprayed at three different concentration(1×106 ,107 and 108 conidia/㎖) in laboratory conditions. 나타내었다.

곤충병원세균(Bacillus thuringiensis: 비티)의 살충효과를 증가시킨 미생물살충제 “비티플러스”가 개발되었다. 그러나 수화제 형태의 비티플러스는 농가나 산업체에서 높은 단가로 선호하지 않고 있는 실정이다. 이에 본 연구는 액상 제형의 비티플러스를 개발하는 연구 목적을 두었다. 이러한 목적에 따라 먼저 비티플러스 제조에 포함되는 두 세균 배양액의 최적 혼합 비율을 결정하였다. 이 최적 혼합액은 10%의 에탄올을 보존제로 사용되었으며, 비티와 또 다른 곤충병원세균인 Xenorhabdus nematophila (Xn)의 배양액 비율이 5:4 (v/v)로 제조하게 했다. 또한 이 액상제형이 1,000 희석배수에서 효과를 보이기 위해 비티 배양액을 10 배 농축하여 최적 비율로 혼합하였다. 이렇게 해서 얻어진 액상 제형을 발육 후기 유충의 배추좀나방(Plutella xylostella)이 가해를 하는 배추밭에 처리하여 7일 후 약 77%의 방제 효과를 보였는데, 이 처리 효과는 현재 상용화되는 배추좀나방 적용 생물농약들과 비등한 효과를 나타내는 것으로 판명되었다. 저온 및 상온의 저장 분석에서 본 액상 제형은 최소한 한 달 동안 안정된 방제효과를 나타내는 것으로 분석되었다. 이 액상 제형의 안정된 방제 효과를 보장하여 주는 품질관리 기술을 개발하기 위해 제형 내비티 포자 밀도와 Xn 유래 유용물질의 농도를 판별하였다. 본 연구 분석은 최적의 방제 효과를 나타내기 위해서는 비티플러스 액상 제형에 비티 포자 밀도가 최소 5 × 1011 spores/mL 이고, Xn 세균 대사물질들 가운데 8 종 유효물질의 농도가 품질관리 판별 기준으로 제시되었다.

Beet armyworm, Spodoptera exigua are difficult to control using chemical insecticides because of the development of insecticide resistance. For eco-friendly beet armyworm managements, various control agents are required. Entomopathogenic fungus is one of promise control agents as an alternative to chemcal control agent. We conducted bioassays with entomopathogenic fungi to select high virulence isolate to larva of beet armyworm. The bioassay was used 150 entomopathogenic fungal isolates which were isolated from soil samples of nine provinces by insect-bait method using Galleria mellonella and Tenebrio molitor. . Three isolates, Metarhizium spp. FT83, FT89 and FT90 had high virulence as 84.6%, 100% and 100%, respectively, against S. exigua. The medial lethal time(LT50) of conidia of three isolates was 5.01, 2.99 and 2.92days respectively.

국내 배추좀나방(Plutella xylostella) 집단은 피레스로이드 농약에 대해서 저항성을 보이며, 이는 이 살충제의 작용점인 소듐이온채널 유전자의 돌연변이에 기인된다. 더욱이 배추좀나방은 대부분 상용화된 살충제에 대해서 저항성을 발달시킬 수 있다. 본 연구는 배추좀나방을 효과적으로 방제하기 위해 내부기생성 천적인 프루텔고치벌(Cotesia plutellae)과 미생물농약인 Bacillus thuringiensis의 혼합처리 기술을 개발하기 위해 수행되었다. 프루텔고치벌이 감수성과 저항성 배추좀나방에 대한 기생 선호성에 차등이 있는 지 조사하기 위해 다섯 개 서로 다른 집단에 대해서 살충제 감수성과 프루텔고치벌 기생성 차이를 비교하였다. 이들 배추좀나방 집단들은 피레스로이드, 유기인계, 네오니코틴계 및 곤충성장조절제를 포함하는 세 종류의 상용 살충제에 대한 약제 감수성에서 뚜렷한 차이를 보였다. 그러나 이들 집단들은 프루텔고치벌에 의한 기생률에서는 차이를 보이지 않았다. 더욱이 기생된 배추좀나방은 B. thuringiensis에 대해서 감수성이 증가되었다. 프루텔고치벌이 갖는 면역억제인자 가운데 바이러스 유래 ankyrin 유전자(vankyrin)를 비기생된 배추좀나방에 발현시켰다. Vankyrin의 발현은 배추좀나방 3령충의 B. thuringiensis에 대한 감수성을 현격하게 증가시켰다. 즉, 프루텔고치벌에 의해 야기된 면역저하가 B. thuringiensis의 살충력을 증가시켰다. 이러한 결과들은 프루텔고치벌과 미생물농약인 B. thuringiensis의 혼합처리가 살충제 저항성 배추좀나방을 효과적으로 방제할 수 있다고 제시하고 있다.

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.

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.

This study was carried out investigate to availability of commercial microbial pesticide and antibacterial activity of isolates isolated from different mushroom media. Ten commercial microbial pesticide and EM liquid were collected from different company. EM of these one has been used for control of mushroom disease and growth promotion at the mushroom farms. The density of bacteria and yeast in EM cultural liquid was higher than those of the crude liquid. The pH values of EM showed the low acid levels(pH 3.5~3.9) by organic acid secreted from microorganism. The kinds of organic acid was acetic acid, lactic acid and succinic acid. The dominant bacteria isolated from EM liquid was Lactobactillus sp.(21 strains), Acetobacter sp.(9 strains), PaeniBacillus sp.(9 strains) and others(12 strains). The organic acid bacteria isolated from fermentation foods( was 92 strains and the dominant genus was Weissella sp.(41 strains), Leuconostoc sp.(21 strains), Enterococcus sp.(9 strains), Lactococcus sp.(9 strains) and others(12 strains). And we isolated 2,500 bacteria from oyster mushroom and button mushroom cultural media for selection of antagonistic bacteria. Thirty five strains of these isolates showed very strong antagonistic activity. These strains were identified Bacillus amyloliquefaciens, Bacillus subtilis, Brevibacterium halotolerans, Pseudomonas libanensis, Stenotrophomonas maltophilia and Alcaligenes faecalis by 16S rDNA analysis.

Due to internal feeding behavior, the oriental tobacco budworm, Helicoverpa assulta (Guenée), infesting hot pepper has been regarded to be effectively controlled by targeting egg and neonate larval stages just before entering the fruits. This study aimed to develop an efficient biological control method focusing on these susceptible stages of H. assulta. An egg parasitoid wasp, Trichogramma evanescens Westwood, was confirmed to parasitize the eggs of H. assulta. A mixture of Gram-positive soil bacterium, Bacillus thuringiensis subsp. kurstaki, and Gram-negative entomopathogenic bacterium, Xenorhabdus nematophila ANU101, could effectively kill neonate larvae of H. assulta. A sex pheromone trap monitored the occurrence of field H. assulta adults. The microbial insecticide mixture was proved to give no detrimental effects on immature development and adult survival of the wasp by both feeding and contact toxicity tests. A combined treatment of egg parasitoid and microbial pesticide was applied to hot pepper fields infested by H. assulta. The mixture treatment of both biological control agents significantly decreased the fruit damage, which was comparable to the chemical insecticide treatment, though either single biological control agent did not show any significant control efficacy. This study also provides morphological and genetic characters of T. evanescens.

This study was aimed to determine microbiological quality by adding green tea extracts to chicken meat salad. For this study, Chicken meat salad were prepared with two production method. (method 1: addition of green tea extracts to boiling phase, method 2: addition of green tea extracts to salad dressing) Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and Aw and determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during holding at 3, 10, 25±1℃ for 12 hours. Green tea extracts improved the microbiological quality and showed antibacterial properties when they are added to chicken meat salad.