高通量测序解析冰鲜刀鲚细菌群落变化特征

为了研究养殖刀鲚冰鲜保存过程中细菌群落组成及变化情况，采用Illumina Miseq高通量测序方法对冰鲜条件不同贮藏时间（0、3、6、9、12、15、18 d）刀鲚肌肉样本细菌的16S rRNA基因的2个高变区（V3—V4）进行测序，比较其细菌多样性及门、属水平的细菌相对丰度，并进行主成分分析、Heatmap分析以及特定腐败菌分析。结果显示，7组样品细菌分布于40门787属，冰鲜条件下刀鲚肌肉的优势致腐败菌属为假单胞菌、微杆菌属和气单胞菌属。主成分分析显示，刀鲚腐败前后的微生物结构存在差异。Heatmap图分析显示新鲜样本的细菌丰度最大。3组冰鲜贮藏6 d前的样品群落结构较相似。贮藏12 d时常见致腐菌（微杆菌属、假单胞菌属、气单胞菌属）占比显著提高，其细菌的多样性及丰富度最低。随着冰鲜保存时间的延长，刀鲚肌肉的细菌菌落结构产生了动态变化。冰鲜保存6～9 d后刀鲚肌肉的细菌菌落结构变化较大，研究结果可以为预测冰鲜刀鲚货架期提供参考。

Characteristics of Coilia nasus bacterial community change during chilled storage analyzed by high-throughput sequencing

In order to analyze cultured Coilia nasus muscle microbial structure and dynamics of bacterial community during the chilled storage, Illumina MiSeq high-throughput sequencing method was used to analyze the two high-variation regions (V3-V4) of 16S rRNA gene of bacterial structure from the muscle samples of C. nasus in chilled conditions stored at different storage time (0, 3, 6, 9, 12, 15, 18 d), and to compare the bacterial diversity and relative abundance at phylum and genus levels, as well as to conduct principal component analysis, Heatmap analysis, and specific spoilage bacteria analysis. The results showed that there were 40 phyla, 787 genera bacteria distributing in seven groups, and the dominant spoilage bacteria in the samples of the C. nasus muscle during chilled storage were Pseudomonas, Exiguobacterium and Aeromonas. Principal component analysis showed that there were differences between the microbial structures before and after spoilage, and Heatmap analysis showed that fresh sample had the highest bacterial abundance, and the community structure of the three groups of samples before 6 days of cold storage was similar. The proportion of specific spoil organism (Pseudomonas, Exiguobacterium and Aeromonas) significantly increased when stored for 12 days, and the bacterial diversity and abundance were the lowest. The bacterial community structure of C. nasus muscle changed dynamically with the extension of preservation time. The changes in the bacterial community structure of C. nasus after 6-9 days chilled storage were significantly, which would provide a reference for predicting the shelf life of C. nasus.