The differences in intestinal microbiota between common and orange-muscle of Haliotis gigantea and dietary influences on abalone's intestinal microbiota

Compared with common abalone, the orange-muscle abalone (Haliotis gigantea) has an enhanced ability to accumulate carotenoids. Feeding on asparagus (Gracilaria lemaneiformis) was critical for maintaining carotenoid contents in H. gigantea muscles. However, whether intestinal microbes play the role in carotenoid accumulation in different colored abalone, and the effects of different diets on intestinal microbes in abalone are unknown. In the study, the differences in intestinal microbiota between abalone with different colors and the effects of different diets on the intestinal microbiota of the abalone were analyzed. The results showed that (1) there was no significant difference in intestinal microbial community composition between the orange-muscle abalone and the common abalone, and (2) the intestinal microbial community composition of abalone fed on asparagus was significantly different from that of abalone fed on kelp (Laminaria japonica). At the genus level, the relative abundance of Psychrilyobacter in the intestinal tract of abalone fed with asparagus was significantly higher than that of kelp-fed groups. Stenotrophomonas and Vibrio were the dominant bacteria at the genus level in abalone fed with the kelp. This result excluded the role of intestinal microbes in different colored abalone and provided clues for further study of the coloration mechanism of abalone.