Clostridium autoethanogenum protein(CAP)is a new single-cell protein source originating from inactivated bacteria.An in vitro digestion experiment and an 8-wk growth experiment were conducted to evaluate the molecular...Clostridium autoethanogenum protein(CAP)is a new single-cell protein source originating from inactivated bacteria.An in vitro digestion experiment and an 8-wk growth experiment were conducted to evaluate the molecular weight distribution of the CAP hydrolysate,and the effects of dietary CAP levels on the growth performance,plasma parameters,hepatic and intestinal health,and the diversity of gutadherent microbiota of largemouth bass(Micropterus salmoides).The fish(initial body weight of 47.99±0.01 g)were fed diets where CAP gradually replaced 0%(CAP0),12.5%(CAP12.5),25%(CAP25),37.5%(CAP37.5)and 50%(CAP50)of low-temperature steam dried anchovy fish meal(LTFM)in the diet.Results showed that the content of peptides below 1,000 Da in the CAP hydrolysate(0.56 mg/mL)was higher than that of the LTFM hydrolysate(0.48 mg/mL).Dietary CAP inclusion had no negative effect on growth performance,while whole-body lipid content significantly reduced in the CAP25 and CAP50 groups(P<0.05).The plasma alanine aminotransferase activities and triglyceride concentrations in the CAP inclusion groups were significantly lower than those in the CAP0 group(P<0.05).The plasma aspartate aminotransferase activity was significantly reduced in the CAP37.5 group(P<0.05).The richness and diversity of the gut-adhesive microbiota and the proportion of Clostridium sensu stricto 12 in the CAP50 group were significantly higher than those in the CAP0 group(P<0.05).Dietary CAP inclusion inhibited inflammatory responses by down-regulating the mRNA levels of interleukin 1b(IL1b),IL10 and transforming growth factor b1(P<0.05)in the liver.The mRNA levels of acetyl-CoA carboxylase 1 were significantly down-regulated in the CAP12.5,CAP25 and CAP37.5 groups(P<0.05),while that of fatty acid synthase was significantly down-regulated in the CAP50 group(P<0.05).These results demonstrate that dietary CAP inclusion could improve the hepatic and intestinal health of largemouth bass,and can be helpful to further develop CAP as a functional feed ingredient.展开更多
基金the National Key R&D Program of China(2019YFD0900200 and 2018YFD0900400)the National Natural Science Foundation of China(32172981 and 31902382)+1 种基金the Agricultural Science and Technology Innovation Programof CAAS in China(CAAS-ASTIP-2017-FRI-08)China Postdoctoral Science Foundation(2021M703544).
文摘Clostridium autoethanogenum protein(CAP)is a new single-cell protein source originating from inactivated bacteria.An in vitro digestion experiment and an 8-wk growth experiment were conducted to evaluate the molecular weight distribution of the CAP hydrolysate,and the effects of dietary CAP levels on the growth performance,plasma parameters,hepatic and intestinal health,and the diversity of gutadherent microbiota of largemouth bass(Micropterus salmoides).The fish(initial body weight of 47.99±0.01 g)were fed diets where CAP gradually replaced 0%(CAP0),12.5%(CAP12.5),25%(CAP25),37.5%(CAP37.5)and 50%(CAP50)of low-temperature steam dried anchovy fish meal(LTFM)in the diet.Results showed that the content of peptides below 1,000 Da in the CAP hydrolysate(0.56 mg/mL)was higher than that of the LTFM hydrolysate(0.48 mg/mL).Dietary CAP inclusion had no negative effect on growth performance,while whole-body lipid content significantly reduced in the CAP25 and CAP50 groups(P<0.05).The plasma alanine aminotransferase activities and triglyceride concentrations in the CAP inclusion groups were significantly lower than those in the CAP0 group(P<0.05).The plasma aspartate aminotransferase activity was significantly reduced in the CAP37.5 group(P<0.05).The richness and diversity of the gut-adhesive microbiota and the proportion of Clostridium sensu stricto 12 in the CAP50 group were significantly higher than those in the CAP0 group(P<0.05).Dietary CAP inclusion inhibited inflammatory responses by down-regulating the mRNA levels of interleukin 1b(IL1b),IL10 and transforming growth factor b1(P<0.05)in the liver.The mRNA levels of acetyl-CoA carboxylase 1 were significantly down-regulated in the CAP12.5,CAP25 and CAP37.5 groups(P<0.05),while that of fatty acid synthase was significantly down-regulated in the CAP50 group(P<0.05).These results demonstrate that dietary CAP inclusion could improve the hepatic and intestinal health of largemouth bass,and can be helpful to further develop CAP as a functional feed ingredient.
