基于高通量测序技术分析微冻凡纳滨对虾的微生物

文章以微冻贮藏的凡纳滨对虾(Litopenaeus vannamei)整虾、去头尾虾和虾仁的表面微生物作为研究对象,采用高通量测序技术鉴定不同贮藏时期样品菌群的组成及变化情况。结果显示:1)各组样品的操作分类单元(Operational taxonomic unit,OTU)随贮藏时间的推移呈下降趋势,贮藏4周后虾仁的OTU数量最少,整虾与去头尾虾的OTU数量相对较多;2)各组样品的赵氏指数(Chao)、艾斯指数(ACE)和香农指数(Shannon)逐渐减小,辛普森指数(Simpson)增加,即贮藏过程中样品菌群丰度和多样性逐渐降低;3)在属水平上,弧菌属(Vibrio)是各组样品的最初优势菌,弓形菌属(Arcobacter)在去头尾虾和整虾中存在较多。微冻4周后,假单胞菌属(Pseudomonas)、希瓦氏菌属(Shewanella)和嗜冷杆菌属(Psychrobacter)成为优势腐败菌;4)属水平上的热图和关键物种分析显示,3种形式的对虾菌种组成和比例有所差异。综上,凡纳滨对虾贮藏时间和形态不同,其表面微生物种类、丰度等差异显著,在冷链流通过程中需要针对性地抑制微生物优势以保障产品品质。

Microbial analysis of Litopenaeus vannamei during partial freezing storage by Illumina high throughput sequencing

Taking Litopenaeus vannamei of different forms(whole shrimp,decapitated shrimp,shrimp meat)as research objects,we applied Illumina high throughput sequencing technology to identify the surface microbial composition and changes of samples during partial freezing storage.The results show that:1)The operational taxonomic units(OTUs)number of all samples decreased with the extension of storage time.After four weeks of storage,the whole shrimp and the decapitated shrimp had more OTUs,and the OTU number in shrimp meat was the least.2)Chao,ACE and Shannon indices of all samples decreased but Simpson index increased,which indicates that the abundance and diversity of samples reduced during the storage.3)At genus level,Vibrio was the main microorganism of all samples at the beginning,and Arcobacter existed more in the decapitated shrimp and the whole shrimp.After four weeks of storage,Pseudomonas,Shewanella and Psychrobacter became the dominant spoilage bacteria.4)The heatmap and key species analysis at genus level show that the composition and proportion of three forms of shrimp samples were different.Therefore,different forms of L.vannamei had different microbial compositions and abundance in various storage periods.It is necessary to inhibit the advantages of microorganisms specifically to ensure the quality of the products during the cold chain process.