基于16S rDNA和ITS测序技术研究酿酒酵母细胞壁对育肥牛肠道微生物的影响

16S rDNA and ITS sequencing reveals the effects of cell walls of Saccharomyces cerevisiae on intestinal microbiota in finishing bulls

【目的】本研究旨在通过16S rDNA和ITS测序技术探究酿酒酵母细胞壁对育肥牛肠道微生物的影响。【方法】选择体重550 kg左右西门塔尔杂交育肥牛40头,随机分为4组,每组10头牛,对照组饲喂基础饲粮,试验1、2、3组每日每头分别在基础饲粮中添加酿酒酵母细胞壁5、10、15 g。试验预试期10 d,正试期94 d,试验结束前7天于晨饲前采集肠道粪便。【结果】16S rDNA分析结果显示:(1)试验3组Chao指数和ACE指数显著高于其他组(P<0.05)。(2)门水平上,厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidota)是主要优势菌门;属水平上,普雷沃氏菌属_9(Prevotella_9)、栖粪杆菌属(Faecalibacterium)、琥珀酸弧菌属(Succinivibrio)、拟杆菌属(Bacteroides)和双歧杆菌属(Bifidobacterium)是主要优势菌属。(3)经过线性判别分析效应大小(linear discriminant analysis effect size,LEfSe),共检测到1个差异物种(LDA≥4.0,P<0.05)在试验2组发挥重要作用。ITS分析结果显示:(1)各组间α、β多样性无显著差异(P>0.05)。(2)门水平上,子囊菌门(Ascomycota)占比50.00%以上,是主要优势菌门;青霉属(Penicillium)、unidentified_Ascomycota_sp.、曲霉属(Aspergillus)、Orpinomyces和散囊菌属(Eurotium)为主要优势菌属。(3)经过LEfSe分析,共检测到8个差异物种(LDA≥3.0,P<0.05),分别有3、3、2个差异物种在对照组、试验2组和试验3组发挥重要作用。【结论】本研究条件下,饲粮添加10-15 g/d酿酒酵母细胞壁提高了育肥牛肠道细菌群落的丰富度,显著增加了有益菌属Provetella_9、弯颈霉属(Tolypocladium)和Torulaspora的相对丰度,有利于优化肠道微生态环境。

[Objective]To explore the effects of cell walls of Saccharomyces cerevisiae on the intestinal microbiota in finishing bulls by 16S rDNA and ITS sequencing.[Methods]A total of 40 simmental crossbred finishing bulls weighing about 550 kg were randomized into 4 groups,with 10 bulls in each group.The control group was fed with a basic diet,and 5,10,and 15 g cell walls of S.cerevisiae were added to the diet of each bull per day in trial 1,2,and 3 groups,respectively.The preliminary trial and trial lasted for 10 days and 94 days,respectively.Intestinal feces were collected 7 days before the end of the trial.[Results]16S rDNA:(1)The Chao and ACE indices in the trial 3 group were higher than those in other groups(P<0.05);(2)Firmicutes and Bacteroidota were the dominant phyla,and Prevotella_9,Faecalibacterium,Succinivibrio,Bacteroides,and Bifidobacterium were the dominant genera;(3)The linear discriminant analysis effect size(LEfSe)revealed one differential species(LDA≥4.0,P<0.05)playing an important role in the trial 2 group.ITS:(1)There was no significant difference in the alpha or beta diversity among groups(P>0.05);(2)Ascomycota with the relative abundance above 50.00%was the dominant phylum.Penicillium,unidentified_Ascomycota_sp.,Aspergillus,Orpinomyces,and Eurotium were the dominant genera;(3)LEfSe revealed 8 differential species(LDA≥3.0,P<0.05),which included 3,3,and 2 differential species playing an important role in the control,trial 2,and trial 3 groups,respectively.[Conclusion]Under conditions of this study,adding 10-15 g/d cell walls of S.cerevisiae in the basic diet increased the richness of intestinal microbiota and the relative abundance of beneficial bacteria Provetella_9,Tolypocladium,and Torulaspora,which were conducive to improve intestinal microecological environment of finishing bulls.