Effects of Seaweed Enzymatic Hydrolysates on Growth and Intestinal Microflora Structure of Larimichthys crocea
This experiment aimed to determine the application effect of seaweeds enzymatic hydrolysate fed La-rimichthys crocea and its impact on host's intestinal microflora.The cage cultured Larimichthys crocea were fed with self-prepared diets supplemented with 0.5％compound seaweeds enzyme hydrolysates and 0.5％kelp enzyme hydrolysates for 8 weeks from November to December 2022 in Ningde sea area,Fujian Province of China,to observe the effects on the survival and weight gain of the Larimichthys crocea and the16S rDNA am-plicon sequencing of intestinal contents was performed using by the NovaSeq PE250 protocol to analyze the composition of the intestinal microflora and the relative abundance of specific microflora.The results showed that 0.5％compound seaweeds enzyme hydrolysates and 0.5％kelp enzyme hydrolysates both could significant-ly increase the survival rate and average weight gain of Larimichthys crocea,and the analysis of intestinal mi-croflora showed that 1 353 amplicon sequence variants(ASVs)were observed in the intestine of Larimichthys crocea in the 0.5％compound seaweeds enzyme hydrolysates group,and they were dominated by Firmicutes,Proteobacteria,Bacteroidota,Fusobacteriota and Actinobacteriota,and only 242 ASVs in the 0.5％kelp en-zyme hydrolysates group,with Firmicutes and Desulfobacterota predominating and Proteobacteria in lower rela-tive abundance in all samples,all of which differed from the 749 ASVs in the control group and the irregular relative abundance of bacterial phyla in all samples;based on the KEGG-based functional analysis of intestinal microflora also showed significant differences in starch and sucrose metabolism,glutathione metabolism,phos-photransferase system,cyanoamino acid metabolism,Huntington's disease and other glycan degradation(P＜0.05).Further analysis revealed that 0.5％complex seaweed enzyme hydrolysates significantly increased the α-diversity of intestinal microflora and promoted the relative abundances of the Bacteroides and butyric acid-syn-thesizing bacteria,while 0.5％kelp enzyme hydrolysates decreased the α-diversity of intestinal microflora but inhibited the growth of Pseudomonas bacteria in the intestinal tract,and in vitro culture test confirmed that algal oligosaccharides could extremely significantly inhibit the growth of Pseudomonas plecoglossicida(P＜0.01).In conclusion,the two kinds of seaweed enzyme hydrolysis prepared in this experiment can regulate the formation of different intestinal microflora in Larimichthys crocea to promote health and growth,which provides data ref-erence for the development of seaweed feed additives for Larimichthys crocea and the research and development of feed additives that improve the health and growth of Larimichthys crocea by adjusting the intestinal microflo-ra.[Chinese Journal of Animal Nutrition,2024,36(3):1819-1833]
万方数据
维普
