Effects of yeast and yeast extract on growth performance, antioxidant ability and intestinal microbiota of juvenile Pacific white shrimp (Litopenaeus vannamei)

Abstract

An 8-week feeding trial was proceeded to assess the effects of yeast and yeast extract on growth performance, anti-oxidant ability and intestinal microbiota of Litopenaeus vannamei. Five diets supplemented with 0% (Control), 3% beer yeast (Y), 0.5% yeast extract (YE0.5), 1% yeast extract (YE1) and 2% yeast extract (YE2) respectively were assigned to L. vannamei (four replicates per diet, 30 shrimp in each replicate, initial body weight 1.38 ± 0.01 g). The results showed higher weight gain and specific growth rate in shrimp fed diet YE2 compared with those fed the Control (P < .05). Both dietary yeast and yeast extract increased condition factor of shrimp (P < .05). Whole body moisture was significantly lower in shrimp fed yeast and yeast extract than those fed diet Control (P < .05). Shrimp fed yeast extract showed higher total antioxidant capacity compared to Control group (P < .05). Shrimp fed diet YE2 obtained higher catalase and glutathione peroxidase activities than those fed diet Control, YE0.5 and YE1 (P < .05). The main phyla in intestine of shrimp were Tenericutes, Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria. With the increasing dietary yeast extract supplementation, the relative abundances of Ruegeria, and its belonging Rhodobacteraceae, Rhodobacterales, Alphaproteobacteria, Proteobacteria in intestine increased gradually, which were significantly higher than those fed diet Control and Y (P < .05). Moreover, yeast and yeast extract significantly increased the Shannon indexes of intestinal microbiota (P < .05). Overall, dietary 2.0% yeast extract supplementation significantly increased growth performance and antioxidant ability of shrimp, also enhanced microbial diversity and microbiota structure in intestine of L. vannamei.