发酵饲料投喂方式对斑点叉尾(鱼回)生长、肠道菌群及代谢组学的影响

Effects of Fermented Feed Feeding Mode on Intestinal Flora and Metabolomics of Channel Catfish(Ictalurus punctatus)

本研究对斑点叉尾(鱼回)(Ictalurus punctatus)的发酵饲料进行了合理饲喂,并确定了其对斑点叉尾(鱼回)生长、肠道菌群和代谢组学的影响。实验设置3组:持续投喂组(A)(即在膨化饲料中持续添加发酵饲料),间隔投喂组即向膨化饲料中按周间隔添加发酵饲料(B),对照组仅投喂膨化饲料(C)。实验共持续6个月。实验结束后,对斑点叉尾(鱼回)进行称重,并用16S rRNA扩增子测序技术和基于液相色谱的代谢组学技术分别检测斑点叉尾(鱼回)肠道菌群组成以及代谢组学。结果显示,间隔投喂组斑点叉尾(鱼回)终末体重(FBW)显著高于对照组和持续投喂组(P<0.05)。间隔投喂组的群落丰富度和多样性最高,持续投喂组群落丰富度最低(P>0.05)。厚壁杆菌门(Firmicutes)、放线菌门(Actinobacteriota)、蓝藻门(Cyanobacteria)、变形菌门(Proteobacteria)、梭杆菌门(Fusobacteriota)、绿弯菌门(Chloroflexi)和异常球菌门(Deinococcota)是优势细菌门。优势肠道菌属包括未命名的叶绿体科中的一个属(norank_f_norank_o_Chloroplast)、分枝杆菌属(Mycobacterium)、鲸杆菌属(Cetobacterium)、罗姆布茨菌属(Romboutsia)、微小杆菌属(Exiguobacterium)和狭义梭菌属(Clostridium_sensu_stricto_1)。代谢组学分析表明,持续投喂组主要通过N-乙酰-D-半乳糖胺显著上调影响肠道菌群半乳糖和磷酸转移酶系统代谢通路(P<0.05),进而影响鱼体对碳水化合物的消化吸收。而间隔投喂组差异代谢产物L-丝氨酸和L-苯丙氨酸显著上调(P<0.05),影响斑点叉尾(鱼回)肠道菌群硫代谢、氨基酸代谢等,继而影响斑点叉尾(鱼回)能量吸收、抗炎症和免疫等能力。本研究为斑点叉尾(鱼回)发酵饲料投喂方式的探索和健康绿色养殖提供了理论依据。

This study performed rational feeding of fermented feed to channel catfish and determined its effects on growth,the intestinal bacterial community,and metabolomics of channel catfish.There were three groups:continuous feeding(A,continuous addition of fermented feed to the puffed feed),interval feeding involving weekly intervals addition of fermented feed added to the puffed feed(B),and the control group only fed the puffed feed(C).The experiment lasted 6 months.Channel catfish were weighed and the intestinal flora and metabolomics were detected by 16S rRNA sequencing technology and liquid chromatography-based metabolomics technology,respectively after the experiment.The final body weight(FBW)of channel catfish was significantly higher in the interval feeding group than that in the control group and the continuous feeding group(P<0.05).The richness and microbial diversity of the intestine was the highest in the interval feeding group,while the richness of the continuous feeding group was the lowest(P>0.05).Firmicutes,Actinobacteriota,Cyanobacteria,Proteobacteria,Fusobacteriota,Chloroflexi,and Deinococcota were the dominant bacterial phyla among the intestinal flora.The dominant intestinal genera included norank_f_norank_o_Chloroplast,Mycobacterium,Cetobacterium,Romboutsia,Exiguobacterium and Clostridium_sensu_stricto_1.Metabolomic analysis showed that the continuous feeding group mainly affected galactose metabolism and the phosphotransferase system of the intestinal flora in channel catfish through the significant upregulation of N-acetyl-D-galactosamine(P<0.05)that affected the digestion and absorption of carbohydrates by fish.The differential metabolites L-serine and L-phenylalanine were significantly upregulated(P<0.05)in the interval feeding group.This affected sulfur metabolism and amino acid metabolism of the intestinal flora,and affected energy absorption,anti-inflammation,and immunity of the channel catfish.This study provided a theoretical basis for the exploration of feeding methods using fermentation feed and healthy green breeding of channel catfish.