生鲜罗非鱼片在冷藏过程中细菌群落演替的PCR-DGGE分析

分析了生鲜罗非鱼片在腐败过程中细菌群落的演替规律。以4℃有氧冷藏条件下的生鲜罗非鱼片为研究对象,定期提取鱼片上的细菌总DNA,采用16S rDNA PCR-DGGE技术连续分析细菌群落演替,对DGGE电泳胶片上的主要DNA条带进行序列分析并构建系统发生树。结果表明:9个主要的DNA条带所代表的细菌来源于以下几个属:希瓦氏菌属(Shewanella)、无色杆菌属(Achromobacter)、不动杆菌属(Acinetobacter)、嗜冷杆菌属(Psychrobacter)、假单胞菌属(Pseudomonas)、短杆菌属(Brevibacterium)、迪茨氏菌属(Dietzia)、紫色杆菌属(Janthinobacterium)、黄杆菌属(Flavobacterium)。在冷藏初期即第0～6d鱼片上的细菌包括8个属,即无色杆菌属、希瓦氏菌属、嗜冷杆菌属、假单胞菌属、不动杆菌属、短杆菌属、迪茨氏菌属、紫色杆菌属;冷藏9d后鱼片发生腐败,此时无色杆菌属、希瓦氏菌属、嗜冷杆菌属和假单胞菌属的细菌成为优势种;冷藏12d时出现黄杆菌属细菌。

PCR-DGGE analysis of bacterial community succession in fresh tilapia fillets during cold storage

This paper aimed at analyzing the succession of bacterial communities in fresh tilapia fillets in the process of putrefaction.Fresh tilapia fillets were stored at 4℃ under aerobic condition.The bacterial communities were periodically analyzed by 16S rDNA PCR-DGGE method.The main DNA bands of DGGE electrophoresis were sliced and used for 16S rDNA sequence analysis.The phylogenetic tree of these bands was constructed base on the results of sequence analysis.Results showed that 9 of the total main DNA bands of DGGE electrophoresis were from the following genera:Shewanella,Achromobacter,Acinetobacter,Psychrobacter,Pseudomonas,Brevibacterium,Dietzia,Janthinobacterium and Flavobacterium.At earlier stage of cold storage,i.e.the period from 0 to 6th day,the bacterial communities in tilapia fillets consisted of 8 genera,including Achromobacter,Shewanella,Psychrobacter,Pseudomonas,Acinetobacter,Brevibacterium,Dietzia and Janthinobacterium.After 9 days cold storage the tilapia fillets putrefied,meanwhile Achromobacter,Shewanella,Psychrobacter and Pseudomonas became the dominant species in tilapia fillets.After 12 days cold storage Flavobacterium appeared in fillets.