Application of two crucial hemicellulolytic enzymes in fish diet: Xylanase and mannanase

Supplementation of hemicellulase to the animal feed is a key strategy for enhancing the nutritional quality of diets containing hemicellulose, such as xylan and mannan. accounting for approximately 6.20 % and 1.86 % of soybean meal ingredients, respectively. Xylanase and mannanase are two crucial hemicellulolytic enzymes, as well as two significant feed enzymes. The beneficial effects and underlying mechanism of dietary hemicellulase inclusion on digesta viscosity, nutrient digestibility, growth performance, immune response, as well as intestinal structure and microbiota of fish fed plant meal have been well demonstrated. However, several issues including delivery effectiveness, the interaction between hydrolysis products and gastrointestinal development, immunity, and microbial colonization, as well as the joint use with other enzymes should be concerned. This review compiles current research findings about the characteristic of xylanase and mannanase, and the effects of dietary xylanase/mannanase on nutritional digestion, immune responses, and overall health of fish, as well as discusses potential approaches to develop the application of hemicellulolytic enzymes in fish diet. It also aims to inspire researchers to explore innovative strategies to enhance the utilization of hemicellulases in aquaculture industry.