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.