Abstract:

The aim of this study was to compare the bacterial community structure of Litopenaeus vannamei in different cultivation environments. An Illumina MiSeq high-throughput sequencing-based method was used for detecting the 16S rRNA gene of the bacterial community in the intestine of L. vannamei and water and sediment samples from cultivation ponds. The results showed that the bacterial community in the intestine of L. vannamei and in the cultivation environment included 62 phyla, 175 classes, 381 orders, 631 families, 1141 genera, and 2035 species. Proteobacteria, Actinobacteriota, and Chloroflexi were the dominant bacterial phyla in the intestine of L. vannamei, with average percentages of 33.67%, 25.33%, and 12.77%, respectively. Proteobacteria, Chloroflexi, and Firmicutes were the dominant bacteria in the sediments, accounting for 28.33%, 17.33%, and 11.13%, respectively. The dominant bacteria in the water were Actinobacteria, Cyanobacteria, and Proteobacteria, with average percentages of 29.33%, 27.0%, and 21.33%, respectively. The abundance-based coverage estimator (ACE) and Chao diversity index of bacterial community in the intestine of L. vannamei were higher than those in the water, while lower than those in the sediments. The bacterial community richness in the intestine of L. vannamei was similar to that in water, but higher than that in the sediments. The Shannon index of the bacterial community in the intestine of L. vannamei was higher than that in the sediments, but lower than that in water. The Simpson index of the bacterial community in the intestine of L. vannamei was higher than that in the sediments but lower than that in the water. Nevertheless, some dominant bacterial species were similar in the intestine of L. vannamei and in the cultivation environment. At the operational taxonomic unit (OTU) level, 1492 identical units were detected in the intestines of L. vannamei and sediments, and 588 identical units were detected in the intestine of L. vannamei and water. Both cluster and principal coordinate analyses showed that the bacterial community in the intestine of L. vannamei was relatively similar to that in the sediments. This study explored the relationship between the bacterial community in the intestine of L. vannamei and its cultivation environment, providing valuable data for the scientific use of environmental probiotics, quality and production, and disease and epidemic prevention.

Key words: Litopenaeus vannamei, high-throughput sequencing, bacterial community structure, 16S rRNA