본 연구는 부패미생물의 종류와 차이를 알아보기 위해 유기농산물과 일반농산물(깻잎, 양배추, 상추)을 구입하여 4oC에 14일 저장한 후 일반목적배지를 사용하여 미생물을 분리 및 16S rRNA sequencing방법을 이용하여 동정하였다. 유기농산물 깻잎, 양배추, 상추의 총균수는 5-7 log10 CFU/g 수준이었고, 일반농산물의 총균수는 5-8 log10 CFU/ g 수준이었다. 유기농산물보다는 일반농산물이 총균수를 더 많이 내재하고 있으나 유의적인 차이는 나타나지 않았 다(p > 0.05). 유기농산물 깻잎에서 발견된 주요 균은 Microbacterium sp.이었으며, 일반농산물 깻잎에서 발견된 주요 균은 Stenotrophomonas maltophilia이었다. 또한, 유기농산물에서 부패를 일으킬 수 있는 균인 Klebsiella pneumonia 가 발견되었으며, 일반농산물보다 유기농산물에서 발견된 균의 종류가 더 많은 것을 확인할 수 있었다. 이에 본 연구 결과는 부패미생물에 대한 이해를 높이고 농산물의 신선도 및 유통기한을 늘리기 위한 새로운 살균소독제 및 부패 억제제를 개발하는데 좋은 기초자료로 사용될 수 있을 것으로 사료된다.

Larvae black soldier fly, Hermetia illucens, is beneficial because its larvae feed on organic materials derived from plants, animals and humans and promote the recycling of food waste and organic materials. Chymotrypsin serine protease is one of the main digestive proteases in the midgut of and is involved in various essential processes. In a previous study, a gene encoding a chymotrypsin-like protease, Hi-SP1, was cloned from the larvae of Hermetia illucens and characterized. The objective of this study was to compare the digestive enzyme activity with various enzymes such as papain, protease and α-chymotrypsin. And also, we investigated the antimicrobial activity of the Hi-SP1 against the spoilage relate bacteria. The growth of the bacteria was inhibited in nutrient broth containing the Hi-SP1.

Blacken spoilage is one of the common problems during the cold storage of dried persimmon in Korea. We collected the spoiled dried persimmon in the refrigerator and classified them to 4 types depending on their appearances. Furthermore we isolated blacken spoilage inducing bacteria from type D of dried persimmons. Among the isolates we identified the seven blacken spoilage inducing bacteria. They are Aeromonas hydrophila DP1, Cedecea davisae DP2, Ewingella americana DP3, Flavimonas oryzihabitans DP4, Providencia rettgeri DP5, Providencia rustigianii DP6 and Serratia plymuthica DP7. Strains were identified based on their morphological, cultural and physiological properties. We also found that Ewingella americana DP3, Flavimonas oryzihabitans DP4 were the major blacken spoilage inducing bacteria during dried persimmon storage.

To develop a lactic starter to produce antimicrobial substance for inhibiting the growth of a variety of foodborne spoilage bacteria in fermented foods, we investigated the antibacterial effect of the antibacterial substance, produced by Lactobacillus amylovorus IMC-1, against foodborne spoilage strains, and its sensitivity on the treatment of proteolytic enzymes. L. amylovorus IMC-1, which was isolated from a traditional cheese in Inner Mongolia, produced a maximum amount of antibacterial substance in the skim milk medium after 72 h incubation at 37℃, and further incubation resulted in the same activity. The substance obtained from gel filtration inhibited all strains used such as Bacillus subtilis IFO 3025, Staphylococcus aureus IAM 1011, Listeria monocytogenes VTU 206, Escherichia coli RB, and Pseudomonas fragi IFO 3458 at the concentration of 20 units/ml. This substance was found to show bactericidal action against B. subtilis, E. coli, and Ps. fragi, and bacteriostatic activity against both Staph. aureus and L. monocytogenes. The bactericidal action was due to cellular lysis. The substance is not organic acid, hydrogen peroxide and proteinaceous compound.

This study was undertaken with packed tofu products to serve as a basic source for sanitary control of tofu production by detecting spoilage bacteria in tofu from which are isolated, investigating heat-resistance and growth characteristics of spoilage bacteria. Isolated strains were confirmed as relevant strains in tofu spoilage, and Strain No. Tl, T2 show 92% probability to be Enterobacter amnigenus, and 96% to be Flavobacterium indologenes according to the result of identifying strains by using Vitek system. Both strains had high viability at 35℃, pH 6.5. In the heat-resistance test of isolated strains, Enterobacter amnigenus T1 was treated for 2 mins, the number remained 56.3% of the initial number at 60℃, 37.8% at 70℃, 34.0% at 80℃ and 22.2% at 90℃, and Flavobacterium indologenes T2 was treated for 2 mins, the number remained 74.8% of the initial number at 60℃, 65.7% at 70℃, 37.8% at 80℃ and 9.3% at 90℃.

강황 에탄올 추출물은 Listeria monocytogenes ATCC 19115, Pseudomonas fluorescens ATCC 21541, Staphylococcus aureus ATCC 29273, Salmonella typhimurium ATCC 21541, Vibrio parahaemolyticus ATCC 17802 그리고 Aeromonas hydrophila KCTC 2358에 대하여 0.05-0.2% 범위에서 뚜렷한 성장억제효