Effect of nitrite exposure on gut microbiota in juvenile Chinese three-keeled pond turtles

More and more experimental results show that high concentrations of nitrite can adversely affect the health of aquatic organisms. In this study, turtles were exposed to different concentrations of nitrite (0,1,10,100 mg / L) to explore the effects of nitrite exposure on the composition and diversity of their intestinal flora. The results showed that nitrite exposure significantly reduced the diversity of intestinal flora. At the phylum level, the abundance of Proteobacteria in the high concentration treatment group (10 and 100 mg / L) increased, while the abundance of Bacteroidetes and Firmicutes decreased significantly. At the genus level, some bacterial genera in the intestine changed significantly after nitrite exposure. These include Prevotella _1, Halomonas, Muribaculaceae _ ge and Aeromonas. Gene function prediction showed that the relative abundance of ansamycin biosynthesis was low in the high concentration treatment groups (10 and 100 mg / L), while the relative abundance of ketone synthesis and degradation increased with the increase of concentration. This study provides a scientific basis for further understanding the effect of nitrite pollution on the intestinal flora of amphibians.