우리나라 고유의 전통발효 식품인 메주로부터 항리스테리아 활성을 나타내는 유산균을 분리한 후 동정한 결과 E. faecium MJ5-14로 명명되었으며, 이들의 박테리오신은 MRS broth중에 37??에서 12-18시간 배양하는 동안 최대의 활성을 나타내었다. L. monorcytogenes KCTC 3569와 KCTC 3710 및 L. ivanovii subsp. ivanovii에 대한 박테리오신의 활성은 640 BU/mL이었고, L. innocua ATCC 33090, L. ivanovii ATCC 19119, L. grayi KCTC 3581 및 L. seeliger KCTC 3591에 대한 활성은 1280 BU/mL으로 나타났다. L. monocytogenes KCTC 3569와 E. faecium MJ5-14을 혼합 배양한 경우 L. monocytogenes의 감소 효과는 25?? 이하 보다는 E. faecium MJ5-14 박테리오신 생산 최적 온도인 37℃에서 더 높게 나타났으며, f. Jhrrf'um MJ5-1꾸T 박테리오신 항균 효과는 1. mouoryrogenrrKCTC 3569의 초기 균수와 첨가한 박테리오신의 양에 따라 좌우되어 교. mouocyrogrurr의 초기 균수가 적고, 박테리오신의 첨가량이 많을수록 항균효과가 높아짐을 될인하였다. 또한 박테리오신 70 BU/mL첨가에 의한 항균 효과는 균 증식이 활발한 대수증식기 중반 이후 보다는 유도기 내지는 대수증식기 초반부에 더 크게 나타났다. 한편,박테리오신 25 BU/CL을 첨가에 의해선 고. HororyrDfrurr KCfC 3569세포벽의 일부가 얇아rl고, 50 BU/DL 이상의 농도에 의해선 세포막이 파괴되면서 세포 내용물의 유출 현상이 관찰되었다.

Paralytic shellfish poison (PSP) occurrence and variation in the different bivalve species including oyster, Crassostrea gigas and mussel, Mytilus edulis in Jinhae bay Korea from January to December in 1997 were surveyed. And also compositional characteristics of PSP ingredients in the different bivalve species were investigated. PSP in shellfish was detected from late February and increased continuously until the middle of April in Jinhae bay. And after April PSP level had been decreased gradually and the toxicity was not detected by mouse bioassay in the early of June. Of the examined bivalve species, PSP content in the mussel exhibited the highest value and the PSP content in the mussel in the middle of April, PSP high season in Jinhae bay, was 6 times higher than that in the oyster. Gonyautoxin (GTX)1-4 group occupied 59.0-78.8% of whole PSP contents and identified as dominant ingredient in the examined bivalves except oyster. And it is also identified that the PSP toxicity in the tested species were derived from the GTX group. And the dominant ingredient of PSP in the oyster was carbamoyl-N-sulfo-llα- hydroxysaxitoxin sulfate(C1)(37.9%) and neosaxitoxin(neoSTX)(26.2%). But the toxicity of C1 in the tested oyster could be ignorable and most toxicity (80.0%) was derived from saxitoxin (STX) group.

To investigate the effects of bacterial endotoxin on lipids and cytokines, and to explain the relationships between their changes, we carried out this study using experimentally Escherichia coli (E. coli) endotoxin-induced septicemic rabbits. The triglyceride and cholesterol concentrations in endotoxin groups were generally high (p$lt;0.01 or 0.05) at all sampling time points (from 3hr to 24 hr), while phospholipid concentrations in endotoxin groups elevated in dose-dependent fashion at 3hr and 6hr after endotoxin injection compared to control group (p$lt;0.05). There were significant negative correlations between lipids changes and cytokines (TNF-α and IL-1β) each other (p$lt;0.05), and endotoxic rabbits having higher triglyceride of cholesterol levels shown relatively better conditions compared with others. As a result, the alterations in the lipid compositions caused by endotoxin may imply an active exhibition of the host defense mechanism rather than the disturbances of lipid metabolism.

In previous reports, the authors isolated the algicidal marine bacterium, Alteromonas sp. SR-14 and demonstrated its growth inhibition of diatom, Chaetoceros calcitrans (C. calcitrans). In this paper, we studied the effects of cell free culture filtrate of Alteromonas sp. SR-14 on the growth of C. calcitrans, and the characteristics of the algal growth inhibition substance. The culture filtrate of Alteromonas sp. SR-14 grown in peptone broth showed growth inhibition activity against C. calcitrans. The reasonable culture conditions of the bacterium for producing of algal growth inhibition substances were 15-20℃ in temperature, 7.0-9.0 in pH and 23-30‰ in salinity, respectively. The algal growth inhibition activity of culture filtrate was increased from stationary phase in growth curve of Alteromonas sp. SR-14. The molecular weights of algal growth inhibition substances produced by Alteromonas sp. SR-14 were ranged about from 3 KDa to 12 KDa. Among the substances, less than 10 KDa fraction were stable by heating at 100℃ for 10 minutes, while more than 10 KDa fraction were heat labile. According to the experimental results, the algal growth inhibition substance produced by the bacterium was not a single compound.

In order to develop antimicrobial substances, many kinds of medicinal herbs were extracted with absolute ethanol and then antimicrobial activities against various microorganisms were investigated. Ethanol extract from cinnamon bark showed the strongest antimicrobial activity on the growth of almost all submitted microorganisms. Specially, molds such as Aspergillus sp. and Pencillium sp. were inhibited strongly. Therefore, the crude antimicrobial substance from the ethanol extract was fractionated with various solvents such as n-hexane, chloroform, ethyl acetate, and n-butyl alcohol and then their antimicrobial activities were tested. Among the various solvent fractions from the ethanol extract, n-hexane fraction was the best in antimicrobial activity especially against molds. There were no significant changes in antimicrobial activity of the n-hexane fraction by heat treatment at 100℃ for 60 min or 121℃ for 15 min and by the change of pH 4.0-10.0. We could get the results that the n-hexane fraction of cinnamon bark extract showed not only antimutagenicity but also no mutagenicity by Ames test with Salmonella typhimurium TA 98 and TA 100.

Citrus펙틴을 효소로 가수분해시켜 얻은 펙틴분해물은 분해율이 35%가 되면서부터 항균력이 서서히 나타나기 시작하여 70% 이상에서는 급격히 증가하였으며 완전분해(100%)된 펙틴분해물을 배지에 2.0% 첨가하면 35℃에서 24시간까지 Escherichia coli ATCC l1229의 생육을 완전히 억제하였다. 펙틴분해물의 항균력은 pH 4.9~5.5 범위에서 가장 좋았으며 균종별로는 젖산균을 제외한 대부분의 세균에 대하여 강한 항균력을 나타내었고 젖산균과 곰팡이류에 대해서는 항균효과가 약하였으며 효모에 대하여는 전혀 영향을 미치지 않았다. 즉, 대부분의 세균은 펙틴분해물을 2.0~3.0% 첨가하므로써 35℃에서 48시간까지 생육이 완전히 억제되었으나, Lactococus lactis ATCC 19435, Lactobacillus bulgaricus, Penicllium funiculosum ATCC l1797은 대조구에 비하여 30~40%만이 억제되었으며 Saccharomyces formosensis와 Saccharomyces cerevisiae는 전혀 영향을 받지 않았다. 한편, glycine, ethanol, sodium ascorbate, sodium chloride 또는 sodium acetate 등의 화학보존료를 병용하면 펙틴분해물을 단독으로 사용하였을 때 보다 항균력이 상승하였다. 김치에 펙틴분해물을 1.0% 첨가하여 4℃에 저장하면 섭취하기에 알맞은 김치의 pH를 유지하는 기간이 대조구에 비하여 적어도 15일 이상 연장되었다. 또한 빵속에 펙틴분해물을 1.0%첨가하면 25℃에서 저장 4일째 대조구에 비하여 4 log cycles 그리고 저장 10일까지도 2 log cycles 정도 균의 성장이 억제되었다. 따라서, 펙틴분해물은 천연식품보존제로 이용가능하며 특히, 젖산균이나 효모에 대해서는 항균작용이 미약하거나 없으므로 젖산균이나 효모를 이용하는 발효식품의 품질보존제로서 아주 유용할 것으로 생각된다. 또한 기존의 화학보존료와 병용하므로써 화학보존료의 첨가량을 감소시킬 수 있다는 점에서도 유용하다고 생각된다.

Vibrio mimicus is a closely related species with V. cholerae, and has been reported to be associated with gastrointestinal infections. Although extraintestinal infections of these vibrios have also been reported in Japan and Southeast Asia. But little research papers on V. mimicus was reported in Korea. Therefore, we tried to isolate V. mimicus from the environmental sea water from April to July in Pusan, Korea. Among the isolated strains, we selected the strongest hemolytic strain and then named V. mimicus SM-9. In this paper, we checked the antibiotic susceptibility and psychrotrophic characteristics of the isolated strain. Hemolytic activity of the hemolysin produced by the isolated strain was also measured. V. mimicus was not detected from the sea water samples in April and May, but its detection rate was relatively high in June and July in Pusan, Korea. The bacteriological characteristics of V. mimicus SM-9 were Gram-negative rods, motile, oxidase positive, Voges-Proskauer negative and sucrose negative. In 23 kinds of antibiotics susceptibility test, V. mimicus SM-9 showed susceptibility to the most of antibiotics submitted while it was resistive against lincomycin, oxacillin, rifampin and vancomycin. Hemolytic activity of the hemolysin produced by V. mimicus SM-9 was highest in stationary phase of the growth curve in BHI broth at 37℃ and its activity was reached 18 HU per ml of culture supernatant. For checking the psychrotrophic property of V. mimicus SM-9, the decreasing rate of the strain in phosphate buffer solution and yellowtail flesh homogenate was examined during the storage at 4, 0, -4 and -20℃. The decreasing rates of the selected strain stored in phosphate buffer solution were greater than those in fish homogenate. Decreasing rates of V. mimicus SM-9 stored in phosphate buffer solution were not significantly different by the storage temperatures. The viable cell counts of the strain were decreased as 5 log cycles after 120 hours at all the tested temperatures. While decreasing numbers of the strain in fish homogenates were 2-4 log cycles after 120 hours. The decreasing pattern of the strain numbers were very slow after 200 hours at all the stored temperatures.

The ethanol extract from the root bark of Morus alba showed the strongest antimicrobial activity on the growth of almost all the tested microorganisms which were food-borne pathogens and food-related microorganisms. In order to isolate and purify of antimicrobial substance extracted from the root bark of Morus albs, the antimicrobial substance from the ethanol extract which exhibited a strong antimicrobial activity was purified by solvent fractionation, silica gel column chromatography, TLC and HPLC. Among the fractions fractionated by 4 kinds of solvents from the ethanol extract, the antimicrobial activity of ethyl acetate fraction had the strongest antimicrobial activity against B. subtilis. Unknown compounds were isolated from the ethyl acetate fraction by silica gel column chromatography, TLC and HPLC and the compounds showed strong absorbance at 207, 217 and 285 nm, therefore, it was supposed to be a kinds of aromatic compound.

The ethanol extract from the root bark of Mores alba showed the strongest antimicrobial activity on the growth of almost all the tested microorganisms which were foodborne pathogens d food-related microorganiama. Therefore, fatty acid composition, amino acid composition and shape change of microorganisms treated with the ethanol extract from the root bark of Mores alba were examined. In effects of treatment with the ethanol extract on the fatty acid compositions of B. aubtilis, S. aureus and E. coli, fatty aicd compositions such as hexadecanoic acid (16:0) and octadecanoic acid (18:0)/octadecadienoic acid (18:2) of the tested strains were increased but pentadecanoic acid (15:0), heptadecanoic acid (17:0) and octadecenoic acid (18:1) of E. subtilis, pentadecanoic acid (15:0) of S. ctureus and hexadecenoic acid (16:1) and octadecenoic acid (18:1) of E. coli were decreased. The ethanol extract did not significantly affect the amino acid composition of the tested strains. Tranamisaion electron micrographa of microorganisms treated with the ethanol extract exhibited morphological changes that irregularly contracted cell surface in S. aureus and destructed cell walls in B. subtilis and E. coli.

In order to develop a natural food preservative, the root bark of Morus alba was extracted with several solvents, and then antimicrobial activity was investigated. The optimum extracting condition for the antimicrobial substance from the sample, minimum inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. The antimicrobial activity of the ethanol extract from the sample was atronger than those of the extracts by the other solvents such as water, methanol, ethyl acetate and acetone. The optimum extracting condition for antimicrobial substance from the sample was shaking extraction twice for 5 hours at room temperature in case of 7 times of absolute ethanol added to the crushed root bark of Morus albs. The ethanol extract from the root bark of Mores albs had strong antimicrobial activity against Gram positive bacteria(MIC, 6.4-19.2 g/ml) such as B. subtilis, B. cereus, L. monocytogenes and S. aureus. Especially, Bacillus species was the most susceptible to the extracted substance. The ethanol extract showed antimicrobial activity against Gram negative bacteria(MIC, 160-1600 g/ml) and yeasts(MIC, 1600 g/ml) such as C. albicans and S. acidifaeciens. The extract also showed growth inhibition against molds such as A. niger, A. parasiticus, A. versicolar and T. uiride.

Bacteriocins from lactic acid bacteria have attracted much attention in recent years because of their useful worth in increasing safety and extending shelf life of foods. These substances show an inhibitory effect against some food spoilage bacteria and food-borne pathogens. The inhibitory effect of the bacteriocin produced by lactic acid bacteria against Listeria monocytogenes(L. monocytogenes) was examined in this study. The culture supernatants of 5 kinds of bacteria among the 10 kinds of tested lactic acid bacteria had the inhibitory activity against Listeria sp., various Gram positive and Gram negative bacteria. Bacteriocin produced by Lactobacillus plantarum(Lact. plantarum) LMG 7945 was the most active toward L. monocytogenes. Bacteriocin production of the Lact, plantarum LMG 7945 cultured on MRS broth was increased late logarithmic phase over early stationary phase. This bacteriocin was stable at heat treatment and acidic pH relatively; The activity was retained after heating at 121 for 15min and was active in the pH range of 2-4 but was lost above pH 5.

The effect of the ethanol extract from salviae miltiorrhizae radix (Salvia miltiorrhiza) on the microbial growth and the stability of the extracted antimicrobial material were investigated. The ethanol extract had strong growth inhibition activity (MIC, 3.13-50.0 pg/ml) against Gram-positive bacteria such as B. subtilis, L. monocytogenes and S. aureus. Among Gram-positive bacteria tested, B. subtilis was the most susceptible to the extracted substance. While the antimicrobial activity of the ethanol extract was weak (MIC, 400-800 ug/ml) to E. coli and yeasts (C. albicans. Sacch. diastaticus). The ethanol extract had bactericidal action at higher concentration than MIC against B. subtilis, while the extract had only bacteriostatic action against S. aureus. The extracted antimicrobial substance was stable in the pH range of 4.0 to 10.0, heat treatment at 121℃ for 15 min, and freezing and thawing