| Project/Area Number |
14560166
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fisheries chemistry
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KAWAI Yuji Hokkaido Univ., Grad.School of Fish., Assoc.Prof., 大学院・水産科学研究科, 助教授 (60195039)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Norio Hokkaido Univ., Grad.School of Fish., Prof., 大学院・水産科学研究科, 教授 (60002086)
YAMAZAKI Koji Hokkaido Univ., Grad.School of Fish., Assoc.Prof., 大学院・水産科学研究科, 助教授 (40250500)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | Listeria monocytogenes / fishery product / Carnobacterium piscicola / bacteriocin / biopreservative / 水圏環境 / イカ塩辛 / ストレス耐性 / VBNC |
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| Research Abstract |
Behavior of Listeria monocytogenes in aquatic environment and fishery products, and applicability of biopreservation to control of L.monocytogenes in the products were investigated. In aquatic environment, L.monocytogenes was detected in a river with higher nutritional pollution. In seawater L.monocytogenes maintained the culturable state longer at lower temperature and also might enter a viable but nonculturable (VBNC) state. In nutritionally weak condition like seawater, L.monocytogenes cells became more resistant against some stresses than freshly cultured cells.
Inoculated in some fermented fishery products, L.monocytogenes decreased during storage, which was affected by storage temperature, ingredients and inclusion of lactic acid bacteria in the products. As a result of screening for bacteria inhibiting growth of L.monocytogenes, some strains of lactic acid bacteria were isolated from frozen surimi. Carnobacterium piscicola CS526 produced a novel class IIa bacteriocin, piscicocin CS526, which had a molecular mass of 4,430 Da and a unique amino acid sequence of YGNGL at the N-terminal. Carnobacterium sp.Sur602 produced bacteriocin-like substances depending on casein concentration in the medium. The piscicocin CS526 perturbed functions of the cytoplasmic membrane to act bactericidally against L.monocytogenes accompanied with the efflux of K^+ ions, dissipation of membrane potential, and rapid depletion of intracellular ATP. C.piscicola CS526 was effective to inhibit growth of L.monocytogenes in cold-smoked salmon. Bacteriocin and its producer might have potential for biopreservation of fishery products against L.monocytogenes.
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