海产品由于其高营养价值所以极易腐败，而微生物是引起海产品腐败的重要原因。本研究通过对腐败海鲶鱼中的腐败菌进行分离鉴定，得到乙酰微小杆菌、约氏不动杆菌、考克氏菌属、节杆菌属、施氏假单胞菌、枯草芽孢杆菌、速生嗜冷杆菌和洛菲不动杆菌等菌株。采用三种不同的生物防腐剂（ε-聚赖氨酸、乳酸链球菌素和溶菌酶）对分离出的菌株进行最小抑菌浓度实验，分析其抑菌效果。运用响应面法，复配出最优组合的生物防腐剂，其配比量为ε-聚赖氨酸367.5 mg/kg、乳酸链球菌素375.0 mg/kg、溶菌酶235.0 mg/kg。通过扫描电镜观察，复配剂可以破坏枯草芽孢杆菌细胞膜的完整性，增加细胞膜的通透性。将优化的复配剂应用于海鲶鱼肉保鲜，通过测定菌落总数、pH值和TVB-N等指标，对其防腐抑菌效果进行验证。实验结果表明，在4 ℃储存条件下，添加复配剂的鱼肉的货架期相比未添加的延长了一倍。

Seafood is susceptible to spoilage due to its high concentration of nutrition. Microorganisms play a key role in the spoilage of most seafood. Eight microbial strains were isolated from spoiled Sea catfish in this study, which were identified to be Exiguobacterium acetylicum, Acinetobacter johnsonii, Kocuria sp., Arthrobacter creatinolyticus, Pseudomonas stutzeri, Bacillus subtilis, Psychrobacter celer and Acinetobacter lwoffii. Minimal inhibitory concentrations (MIC) of 3 bio-preservatives (ε-polylysine, Nisin and lysozyme) on the isolated strains were determined. The inhibitory of total bacteria counts by combined bio-preservatives were optimized by response surface methodology. The optimized concentration of ε-polylysine, Nisin and lysozyme was 367.5, 375.0 and 235.0 mg/kg, respectively. The combined bio-preservatives damaged the bacterial cell membrane integrity and increased bacterial membrane permeability of Bacillus subtilis, evidenced by scanning electron microscopy. Total bacteria counts, pH value and TVB-N of Sea catfish with an optimized combined bio-preservative were determined to verify the antibacterial effect, which showed shelf life of Sea catfish with combined bio-preservatives was about twice as long as control both stored at 4 ℃.

国家自然科学基金资助项目（21276197）；国家科技支撑计划项目（2015BAD16B04）