Effects of rice-fish symbiosis on the muscle nutrition, intestinal microbes, liver metabolism and of yellow catfish (Pelteobagrus fulvidraco)

AbstractTo investigate the effects of different rice growth periods and different farming modes on the muscle nutrition, intestinal microbes and liver metabolome profiling of yellow catfish in rice-fish symbiosis. 16S rDNA and non-targeted metabolomic methods were used to analyze the differences of muscle amino acids and fatty acids, intestinal microbes’ diversity and liver metabolome profiling of yellow catfish in the rice pre-anthesis paddy group (aRY_tac), the rice post-anthesis paddy group (bRY_tac), the post-harvest paddy group (cRY_tac) and the post-harvest pond group (dRY_tac). The result showed that the muscle total amino acids (TAA), non-essential amino acids (TNEAA), and umami amino acids (TDAA) in bRY_tac group were significantly (P < 0.05) higher than those in other groups, the muscle saturated fatty acids in dRY_tac group were significantly (P < 0.05) higher than those of other groups, and the content of monounsaturated fatty acids in cRY_tac group was significantly higher than that of the other groups (P < 0.05). The dominant bacteria in aRY_tac group wasPseudomonas, in bRY_tac group wereClostridium,OxyphotobacteriaandBrevundimonas, in cRY_tac group wereCetobacteriumandCandidatus_Arthromitus, and in dRY_tac group wasPlesiomonas. Yellow catfish cultured in rice-fish symbiosis mode possessed higher abundance and diversity of intestinal microbes than that in pond mode. Moreover, under rice-fish symbiosis mode, compared with the rice pre-anthesis and post-harvest periods, yellow catfish in rice post-anthesis’s period showed higher abundance and diversity of intestinal microbes and the liver metabolic phenotype, especially in Arginine biosynthesis, Monobactam biosynthesis, Cysteine and methionine metabolism and amino acids biosynthesis, etc. Our study suggested that different rice growth periods in the paddy field had different effects on the muscle nutritional components, microbial diversity and liver metabolism of yellow catfish, the fish nutritional quality in rice post-anthesis periods would be better. This study provides a theoretical reference for the cultivation of yellow catfish under rice-fish symbiosis system.