基于高通量测序技术分析青藏高原牦牛和犏牛乳中微生物多样性的研究

Study on Microbial Diversity in Milk of Yak and Cattle-Yak in Qinghai-Tibet Plateau Based on High-throughput Sequencing Technology

为探究牦牛和犏牛生鲜乳中微生物的组成和多样性,采用高通量测序技术分析两种生鲜乳的16S rDNA V4区域,并进行生物信息学对比分析。结果显示:97%的一致性共得到5516个OTUs,微生物门水平的比较表明变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)及放线菌门(Actinobacteria)为牦牛乳和犏牛乳共同的优势菌门,牦牛乳三种微生物的相对丰度分别为29.80%、35.99%及8.41%,犏牛乳为45.36%、25.79%及7.39%;在属水平上,牦牛乳的优势菌属为未分类的蓝藻细菌属(unidentified-Cyanobacteria),相对丰度为9.32%,犏牛乳的优势菌属为慢生根瘤菌属(Bradyrhizobium),所占比例为11.53%;在种水平上,埃尔坎尼中慢生根瘤菌种(Bradyrhizobium elkanii)和Kosakonia oryzae为牦牛乳和犏牛乳中共有的优势菌种,两种菌种在牦牛乳中分别占比2.42%、3.36%,在犏牛乳中分别占比11.53%、5.53%;Alpha多样性分析表明不同牛乳丰度估计值存在显著差异(P<0.05),且犏牛乳的丰富度及多样性较高。

This study aimed to explore the composition and diversity of microorganisms in raw milk of yak and cattle-yak.The 16S rDNA V4 region of those two kinds of raw milk was sequencing by high-throughput technology and comparative analysis of bioinformatics.The results showed that a total of 5516 OTUs were obtained with 97%similarity level.The comparison of microbial phylum levels shows that Proteobacteria,Firmicutes and Actinobacteria were the common dominant bacteria phylum for yak milk and cattle-yak milk.The relative abundances of the three Microbes in the yak milk were 29.80%,35.99%and 8.41%,respectively.The relative abundances of the three microbes in the cattle-yakmilk were 45.36%,25.79%and 7.39%,respectively.At the genus level,the dominant genus of yak milk was unidentified-Cyanobacteria,and the relative abundance was 9.32%.The dominant genus of cattle-yak milk was Bradyrhizobium,which accounts for 11.53%.At the species level,Bradyrhizobium elkanii and Kosakonia oryzae were the dominant strains in milk of yak and cattle-yak.The two strains accounted for 2.42%and 3.36%in yak milk,respectively.And the two types of bacteria account for 11.53%and 5.53%of the milk in the cattle-yak,respectively.Alpha diversity analysis shows that there are significant differences between different milk richness estimates(P<0.05).And the richness and diversity ofcattle-yak milk was higher.