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

摘要:

【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。

Abstract:

[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, andTorulaspora, which were conducive to improve intestinal microecological environment of finishing bulls.