Comparison of Pediococcus pentosaceus YC64-fermented soybean meal and raw soybean meal in diets for Nile tilapia: Growth performance, feed utilization, and intestine health

Fermentation is a promising approach for improving the utilization of soybean meal (SM) by aquaculture fish, and the strain is the core of microbial fermentation processes. Herein, Pediococcus pentosaceus YC64, an autochthonous probiotic isolated from the intestine of Nile tilapia (Oreochromis niloticus), was applied to the fermentation of raw SM. In an eight-week feeding trial, tilapia juveniles were divided into two treatments fed on diets with 0 % (Control) and 100 % of SM protein replaced by fermented SM (FSM). Results showed that solid-state fermentation improved SM quality indicated by increased acid-soluble protein contents. Fish fed the FSM diet had significantly higher weight gain, feed efficiency, and protein efficiency compared to those fed the SM diet. Furthermore, whole-body protein content significantly increased in the FSM-fed fish, accompanied with the increased amino acid transport and reduced protein catabolism. Texture profile analysis indicated that fish fed the FSM diet had reduced muscle hardness compared with the control, which was associated with changes in collagen deposition and myofiber development. Moreover, feeding an FSM diet enhanced goblet cell proliferation and stimulated mucin secretion, ultimately leading to improved intestinal tight junctions and reduced inflammatory response. Besides, the FSM diet feeding altered intestinal microbiota community, characterized by increased abundance of Pediococcus. Overall, P. pentosaceus YC64 exhibits promise as a fermentation strain in the production of FSM. The FSM performed better than SM in improving the growth performance, feed utilization, and intestine health of Nile tilapia.