本研究以真空包装冷藏大菱鲆鱼片为研究对象，通过感官、微生物和化学指标评价其货架期，利用16SrDNA方法对其贮藏初期和末期的微生物分布进行鉴定，并采用报告菌株法检测大菱鲆鱼片贮藏过程中两种类型群体感应信号分子（AHLs和AI-2）的产生情况，检测其优势腐败菌的群体感应类型。结果显示，大菱鲆鱼片在真空包装冷藏环境下可以贮藏9 d，此时细菌总数达6.87 log CFU/g，挥发性盐基氮含量为28.70 mg/100 g。对比初始和末期微生物种类变化，真空包装大菱鲆鱼片冷藏过程中的优势腐败菌主要为希瓦氏菌，其次为肠杆菌科细菌。群体感应信号分子AHLs和AI-2含量随贮藏时间延长而增加。贮藏末期分离的希瓦氏菌均能分泌AI-2信号分子，分泌能力因菌株而异。利用基因手段可从希瓦氏菌中扩增到AI-2的分泌基因luxS，表明luxS在产AI-2菌株中具有一定保守性，可能参与希瓦氏菌的腐败进程。

Vacuum-packaged refrigerated turbot fillets were used as the study object, and their shelf-life was determined by sensory evaluation, microbiological and chemical indicators, and the distributions of microflora at the beginning and end of the storage period using a 16S rDNA method. Moreover, two types of quorum sensing signaling molecules (N-acyl homoserine lactones (AHLs) and autoinducer-2 (AI-2)) during the storage of turbot fillets were also detected using reporter strains, and the quorum sensing characteristics of dominant spoilage bacteria were examined. The refrigerated turbot fillets packaged under vacuum conditions could be stored for nine days, and the total viable counts and the total volatile basic nitrogen (TVB-N) value reached 6.87 log( CFU/g) and 28.70 mg/100 g, respectively. The changes in the microbial species over the storage period were examined, and the predominant spoilage bacterium was Shewanella spp., followed by Enterobacteriaceae. The content of quorum sensing signaling molecules (AHLs and AI-2) increased with increasing storage time. All the isolated Shewanella spp. strains were capable of secreting AI-2, while the secretion capacity varied by strains. The luxS gene responsible for AI-2 production was also present, indicating that luxS was relatively conserved in AI-2-producing bacterial strains and AI-2 production may be involved in the spoilage process of Shewanella spp.

国家自然科学基金项目(31071613)