酵母培养物对凡纳滨对虾肠道菌群结构的影响

Effect of Yeast Culture on Intestinal Microbiota of Litopenaeus vannamei

在基础饲料中分别添加质量分数0(对照)和0.30%的酵母培养物,配制2种等氮等脂饲料(分别记为Y0、Y0.3组),投喂初始体质量为(1.20±0.01)g的凡纳滨对虾(Litopenaeus vannamei)56 d。提取凡纳滨对虾肠道总DNA,采用Illumina Mi Seq高通量测序比较样品菌群组成和多样性,研究饲料中添加酵母培养物对凡纳滨对虾肠道菌群结构的影响。结果表明,Y0.3组对虾肠道分类单元(OTUs)数量、丰富度指数(Chao1、ACE值)、多样性指数(Shannon、np Shannon指数)与Y0组差异无统计学意义(P>0.05);从物种分类树发现,两组的主要细菌类群均为变形菌门(Proteobacteria),其中,γ-变形菌纲是对虾肠道的最主要菌群,所占比例达69.48%;从科分类水平看,Y0.3组对虾肠道菌群链球菌科(Streptococcaceae)比Y0组提高4.98%;从优势属水平来看,Y0.3组对虾肠道的乳球菌属(Lactococcus)高于Y0组,差异有统计学意义(P<0.01);Y0.3组对虾肠道的发光杆菌属(Photobacterium)低于Y0组,差异有统计学意义(P<0.05)。饲料中添加质量分数0.30%酵母培养物可改善凡纳滨对虾肠道菌群多样性。

A yeast culture was added to the base diet at mass fraction0(control group)and0.30%,andtwo isonitrogenous and isolipid diets,named Y0and Y0.3respectively,were prepared.Litopenaeusvannamei with an average initial weight of1.20±0.01g were fed with the two diets for56days.Afterthe test,the intestine from Litopenaeus vannamei was extracted in order to acquire the total DNA.Illumina MiSeq high-throughput sequencing was used to compare composition and the diversity ofintestinal flora.Results showed that,though the operational taxonomic units(OTUs)number,Chao,ACE,Shannon and npShannon indexs of Y0.3group obtained higher average value than that of the Y0group,there were no significant difference between Y0.3group and those fed with Y0group(P>0.05).With respect to the phylogenetic tree of species classification,the main bacteria phyla,Proteobacteria,found in the intestine of shrimp fed with Y0.3was similar to the shrimp fed with Y0.The proportion ofclassγ-Proteobacteria in the intestinal microbiota reached69.48%.From the dominant family level ofbacterial community,the number of Streptococcaceae in Y0.3group were higher than those in Y0groupwhich had4.98%.From the dominant genus level of bacterial community,the proportion ofLactococcus in Y0.3group were significantly higher than those in Y0group(P<0.01).The proportionof Photobacterium in Y0.3group were also significantly lower than those in Y0group(P<0.05).It canbe concluded that the addition of dietary0.30%yeast culture improved diversity of intestinal microbiotafor Litopenaeus vannamei.