基于MiSeq技术的枯草期放牧蒙古羊瘤胃细菌多样性分析

Analysis of Rumen Bacterial Diversity in Grazing Mongolian Sheep Using MiSeq Sequencing Technology in Withered Grass Season

为了阐明枯草季节牧草对放牧蒙古羊瘤胃生理功能的影响,明确放牧蒙古羊瘤胃消化的限制性因素,随机选取终年放牧的6只蒙古羊,在枯草期通过口腔采取蒙古羊瘤胃液,利用MiSeq高通量测序技术分析了瘤胃细菌种群的结构和多样性。结果表明,共得到了2 774个操作分类单元(Operational taxonomic unit,OTU),平均每个样品OTU为462.30。放牧蒙古羊瘤胃细菌共有13个门、24个纲、30个目、59个科、85个属被鉴定。在门水平上,厚壁菌门(Firmicutes,58.59%)、拟杆菌门(Bacteroidetes,18.18%)为放牧蒙古羊瘤胃中的优势细菌种群;在科水平上,主要包括瘤胃菌科(Ruminococcaceae,15.43%)、毛螺菌科(Lachnospiraceae,14.86%)和克里斯蒂娜科(Christensenellaceae,11.90%);在属水平上,普雷沃氏菌属(Prevotella,2.89%)和Candidatus saccharimonas(2.89%)是放牧蒙古羊瘤胃中的优势种群。说明冬春季枯草期放牧蒙古羊瘤胃细菌表现出典型的纤维消化菌群特征,因此,为瘤胃菌科和毛螺菌科提供营养,能够有效改善蒙古羊瘤胃的发酵功能,提高其对牧草的消化率。

In order to elucidate the effect of forage grass on physiological function of rumen in grazing Mongolia sheep in withered grass season and make clear the restrictive factors of rumen digestion,six Mongolian sheep grazed all year round were selected randomly in the experiment,during withered grass season,the rumen juice of sheep was extracted through the mouth, and the structure and diversity of bacterial population in the rumen were analyzed by MiSeq high-throughput sequencing technology.A total of 2 774 OTUs(Operational taxonomic unit) were obtained in the experiment, and the average OTUs of each sample were 462.30.The rumen bacteria of grazing Mongolian sheep belonging to 13 phyla,24 classes,30 orders,59 families and 85 genera were observed.Among these rumen bacterial populations,the dominant bacterial phyla were Firmicutes(58.59%) and Bacteroidetes(18.18%).The dominant bacterial families were Ruminococcaceae(15.43%),Lachnospiraceae(14.86%) and Christensenellaceae(11.90%).Prevotella(2.89%) and Candidatus saccharimonas(2.89%) were the dominant bacterial genera.The rumen bacteria of grazing sheep showed typical characteristics of fiber-digesting bacteria during withered grass season in winter and spring.Therefore,the fermentation function of rumen and the digestibility of forage would be effectively improved by providing nutrition for Ruminococcaceae and Lachnospiraceae.