Diversity of gastrointestinal tract microbes in wild Grammoplites scaber collected from the Pearl River Estuary

Grammoplites scaber is a source of highly nutritious marine food. However, studies on microorganisms in their gastrointestinal tract environments are very rare. To discovery the composition and diversity of microbes in gastrointestinal tract environments of wild G. scaber, we collected the intestinal samples from the Pearl River Estuary and studied them based on cultural and uncultural methods. After the amplification, sequencing, and analysis of the V3 regions of bacterial 16S rRNA genes from experimental sample, a total of 456 OTUs were obtained. Results of similar analysis revealed that Proteobacteria and Firmicutes were the most predominant groups at the phylum level and Clostridium was the prevalent genus in their gut environments with accounting for 57.11%. Results of phenotypic and functional prediction based on 16S rRNA gene showed that both beneficial bacteria and potential pathogenic bacteria existed in their gastrointestinal tract environments, and they tended to restrict each other at the ecological function level. This study revealed at firstly the microbial composition and diversity in the gut microenvironment of wild G. scaber , and also provided a basic reference for further study on the core intestinal microflora of teleost. In addition, the discovery of beneficial and harmful bacteria can provide certain reference for the food safety treatment of G. scaber as marine food resources, and provide scientific data support for the development of marine aquaculture industry.