【作者】 王扬蕊； 白凤翎； 励建荣； 吕欣然；

【Author】 Wang Yangrui;Bai Fengling;Li Jianrong;Lü Xinran;College of Food Science and Engineering,Bohai University;

【机构】 渤海大学食品科学与工程学院；

【摘要】 荧光假单胞菌(Pseudomonas fluorescens)和嗜水气单胞菌(A eromonas hydrophila)是有氧冷藏水产品中的优势腐败菌,且其腐败特性均受N-homoserine lactone(AHLs)型群体感应系统的调控。以具有群体淬灭活性菌株YF-2为研究对象,利用琼脂扩散法验证了菌株YF-2对AHLs标品的降解作用并探究了淬灭活性位置。利用热灭活及酸恢复实验探究了淬灭活性物质的类型。以经荧光假单胞菌单菌及其与嗜水气单胞菌混合菌感染的三文鱼块为载体,通过测定三文鱼块pH、持水力、TBA、TVB-N及菌落总数等新鲜度指标的变化,探究淬灭活性物质在实际中对水产品保鲜的作用。结果表明:菌株YF-2对C4-HSL、C6-HSL和C8-HSL信号分子的降解活性均可达到100%,经鉴定为蜡样芽孢杆菌(Bacillus cereus)。淬灭活性物质存在于细胞提取物(Crude cell extract,CCE),初步判断为AHLs酰基转移酶或AHLs氧化还原酶。此外,蜡样芽孢杆菌YF-2 CCE的处理可使三文鱼pH、TBA、TVB-N和菌落总数的上升速度及持水力的下降速度减慢,即可抑制荧光假单胞菌及其与嗜水气单胞菌混合菌的致腐能力,一定程度上延缓三文鱼的腐败,延长其货架期。更多还原

【Abstract】 Pseudomonas fluorescens and Aeromonas hydrophila are dominant spoilage bacteria in aerobic refrigerated aquatic products,and their spoilage characteristics are regulated by N-homoserine lactone(AHLs)-type quorum sensing systems.Taking YF-2 with quorum quenching activity as the research object,the quenching activity of strain YF-2 against AHLs standard product was verified by the agar plate diffusion method and the position of quenching activity was explored.The types of quenched active substances were investigated by heat inactivation and acid recovery experiments.The salmon pieces infected with P.fluorescens and its mixed bacteria with A.hydrophila was used as the carrier to explore the effect of the quenching active substance on the preservation of aquatic products in practical application through the measuring of changes of freshness indicators such as pH,water holding capacity,TBA,TVB-N and total number of bacterial colony in different time.The results showed that strain YF-2 degradation activity on the signal molecule markers C4-HSL,C6-HSL and C8-HSL could be improved up to 100%.And it was identified as Bacillus cereus.Through heat inactivation and acid recovery tests,it was preliminarily determined that the active substance of strain YF-2 was AHLs acyltransferase or AHLs oxidoreductase,and existed in its crude cell extract(CCE).In addition,the treatment of the CCE of B.cereus YF-2 could slower the rising speed of salmon pH value,TBA value,TVB-N value and the total number of colonies and the falling speed of water holding capacity,which could inhibit P.fluorescens and the spoilage ability of the mixed bacteria with A.hydrophila can delay the spoilage of salmon to a certain extent and prolong the shelf life.更多还原