冷藏鱼片中优势腐败菌的分离鉴定

为探讨冷藏7 d鮰鱼片中优势腐败菌的种类,将鮰鱼于4℃无菌冷库中取肉后真空包装放置于4℃冰箱中储藏7 d,从腐败鱼肉中分离出3株细菌,编号x1-1、y1-1、y2-1,进行细菌形态学观察、生理生化检测以及16S rDNA序列测定等研究。结果表明所有菌种均为革兰氏阴性短杆菌,且均为兼性厌氧菌,通过测序结果与系统进化树分析显示:x1-1与嗜水气单胞菌亲缘关系最近,达99.9%;y1-1与维氏气单胞菌亲缘关系最近,达99.79%;y2-1异嗜糖气单胞菌亲缘关系最近,达99.8%。以上各项研究结果表明:x1-1为嗜水气单胞菌;y1-1为维氏气单胞菌;y2-1为异嗜糖气单胞菌。综上所述,冷藏鮰鱼片中优势腐败菌为气单胞菌。

Isolation and Identification of Dominant Spoilage Bacteria in Refrigerated Catfish Fillets

In order to discuss the species of dominant spoilage bacteria in refrigerated 7 d catfish fillets,the squid was taken in a 4℃ sterile cold storage and placed in a vacuum oven at 4℃ for 7 days. Three strains of bacteria,numbered x1-1,y1-1,and y2-1,were isolated from the corrupted fish meat for bacterial morphology observation,physiological and biochemical tests,and 16S rDNA sequence determination.The results showed that all the strains were Gram-negative Brevibacterium spp,and both were facultative anaerobic bacteria. The results of sequencing and phylogenetic tree analysis showed that x1-1 was closely related to Aeromonas hydrophila,reaching 99.9%. The relationship between y1-1 and Aeromonas veronii was up to 99.79%;y2-1 was similar to Aeromonas allosaccharopila,reaching 99.8%.Combined with the above research results,x1-1 is A.hydrophila;y1-1 is A.veronii;y2-1 is A. allosaccharophila.In summary,the dominant spoilage bacteria in refrigerated catfish fillets is Aeromonas.