基于高通量测序分析紫贻贝冻藏过程中菌群组成变化

Bacterial composition analysis of frozen mussels based on high-throughput sequencing

以蒸汽开壳后获得的新鲜紫贻贝肉(FS)、-18℃冻藏1周紫贻贝肉(FS-1)、冻藏3周紫贻贝肉(FS-3)和冻藏9周紫贻贝肉(FS-9)为研究对象,采用DNA抽提试剂盒提取贝肉表面微生物基因进行高通量测序分析。各样本的有效序列区间为31 896~42 812条、操作分类单元(Operational taxonomic units,OTU)范围为289~681,其中OTU最少的是冻藏9周样品,最多的是新鲜紫贻贝肉。分析多样性指数可知,菌群丰富度最低的是冻藏3周紫贻贝肉。在属水平上,各样本优势菌群中均包含弧菌属(Vibrio)。随冻藏时间的延长,葡萄球菌属(Staphylococcus)的占比逐渐降低。冻藏9周时新增希瓦菌属(Shewanella)且相对丰度很大,另外仅新鲜紫贻贝和冻藏9周样本的优势菌群中含有不动杆菌属(Acinetobacter)。

After opening the shell with steam, the microorganisms on the surface of fresh mussel meat(FS),frozen mussel meat at-18 ℃for 1 week(FS-1),frozen mussel meat for 3 weeks(FS-3)and frozen mussel meat for 9 weeks(FS-9)were extracted with DNA extraction kit and then analyzed by high-throughput sequencing.The effective sequences in all samples ranged from 31 896 to 42 812,and the operational taxonomic unit(OTU)ranged from 289 to 681.Among them,the OTU of FS-9 was the lowest,and the OTU of FS was the highest.Diversity index analysis showed that the lowest microflora richness was found in FS-3.At the genus level,the predominant flora of each sample contains Vibrio spp.With the extension of frozen storage time,the proportion of Staphylococcus was gradually decreased.The Shewanella was newly added and relatively abundant after frozen for 9 weeks.In addition,Acinetobacter was only found in samples of FS and FS-9.