腐败希瓦氏菌及其与蜂房哈夫尼亚菌共培养对冷藏大菱鲆的致腐能力

Spoilage Potential of Shewanella putrefaciens and Co-Culture with Hafnia alvei on Turbot(Scophthalmus maximus) Fillets during Refrigerated Storage

本研究将腐败希瓦氏菌SP22及其与蜂房哈夫尼亚菌Ha-01混合菌液分别接种到大菱鲆无菌鱼块中,以微生物及理化参数(菌落总数、挥发性盐基总氮(total volatile basic nitrogen,TVB-N)值、K值、Ca2+-ATPase活力及肌肉蛋白显微结构)为指标,探讨腐败希瓦氏菌SP22及其与蜂房哈夫尼亚菌Ha-01共培养对冷藏大菱鲆的致腐能力。结果表明:在4℃冷藏过程中,随着贮藏时间的延长,各接菌组鱼块的菌落总数、TVB-N值及K值上升速度明显高于空白对照组,且接种混合菌组的上升速度高于接种单菌组;接菌组的Ca2+-ATPase活力下降速度明显高于空白对照组,其中接种混合菌组下降最快;利用扫描电子显微镜可观察到接菌组肌肉蛋白质变性降解速度明显快于空白对照组。腐败希瓦氏菌SP22能够造成大菱鲆的腐败变质,且其与蜂房哈夫尼亚菌Ha-01共培养时能够产生明显的致腐效果。

Sterile turbot fillets were inoculated with Shewanella putrefaciens SP22 in pure culture or in co-culture with Hafnia alvei Ha-01 and then stored at 4 ℃. The microbial and physicochemical indexes（including total viable count（TVC）, total volatile basic nitrogen（TVB-N） value, K value, Ca^2＋-ATPase and ultrastructural change） were measured after different periods of storage. The aim was to evaluate the spoilage potential of the pure and mixed cultures on turbot fillets. The results indicated that the TVC, TVB-N and K values of inoculated fish fillets increased significantly faster than those of the uninoculated control, and the samples inoculated with the co-culture showed the fastest increase. The Ca^2＋-ATPase activity of the inoculated samples decreased significantly faster than that of the control group and the co-culture group showed the fastest decrease. The rate of degradation of muscle proteins in the inoculated samples was clearly faster than that of the control group as observed under scanning electron microscope. In conclusion, Shewanella putrefaciens SP22 could cause turbot spoilage, and when co-cultured with Hafnia alvei Ha-01, it could lead to turbot fillet spoilage obviously during refrigerated storage.