Association of microbiota in the stomach of Sinanodonta woodiana and its cultured soil

The current study aimed to investigate the association of microbial characteristics in the stomach of Sinanodonta woodiana (S. woodiana) and its cultured soil. S. woodiana stomach and its cultured soil were collected in winter 2019. The V3 + V4 regions of the 16S rRNA gene were sequenced to detect microbial diversity. The differences in the dominant species between S. woodiana and soil were also discussed. The results showed that the diversity and richness indices in S. woodiana were significantly higher than those in cultured soil (P < 0.01). At the phylum level, the dominant bacterial community compositions in the two groups were similar and included Proteobacteria, Firmicutes, Bacteroidetes, Cyanobacteria, Fusobacteria, and Acidobacteria. However, the abundance of these phyla was significantly different between the two groups (P < 0.05 or P < 0.01), and Proteobacteria was the most abundant phylum. At the genus level, a total of 1001 genera were identified in the two groups, of which 890 genera were detected in the cultured soil and 549 were detected in the S. woodiana stomach; 452 were unique to the cultured soil, and 111 were unique to the S. woodiana stomach. This result indicated great differences in the bacterial genera between the two groups. Moreover, 17 out of the 20 dominant bacterial genera exhibited statistically significant differences between the two groups (P < 0.05 or P < 0.01). Cupriavidus was the absolute dominant genus in the stomach of S. woodiana, followed by Sphingomonas and Burkholderia. The microorganisms in the stomach of S. woodiana formed a certain inherent bacterial system and were affected by the environment, which is beneficial to nutrition and health. In conclusion, the bacterial compositions were mostly the same between the stomach of S. woodiana and cultured soil, but the relative abundances of the bacterial communities were different. This study will greatly enhance the understanding of the microbial characteristics between the stomach of S. woodiana and the cultured environment, and provide guidance for healthy aquaculture in freshwater.