西藏不同产区曲拉细菌群落结构的比较分析

为探究西藏不同产区传统发酵乳制品曲拉中细菌多样性及其微生物安全性,该研究通过Illumina MiSeq测序平台,对西藏拉萨(LS)、日喀则(RKZ)、山南(SN)、昌都(CD)、林芝(LZ)、那曲(NQ)和阿里(AL)共7个地区的曲拉样品细菌多样性及群落结构进行了系统分析。结果表明,曲拉具有高度的细菌多样性,并且不同地区的样品存在一定的共性和差异。在门的水平上,7个地区的优势菌均集中在厚壁菌门(Firmicutes)和变形菌门(Proteobacteria),其相对丰度分别在(12.82±5.63)%^96.54±1.39%和(3.46±1.39)%^75.09±9.37%。相比门的种类,拉萨(LS)最多,为24个门,阿里(AL)最少,为2个门。在属的水平上,拉萨地区(LS)曲拉样品中的优势菌属为雷尔氏菌属(Ralstonia)、假单胞菌属(Pseudomonas)和苍白杆菌属(Ochrobactrum),其相对丰度分别为(17.25±7.05)%、(16.05±3.22)%和(9.52±3.19)%;其他6个产地的曲拉样品中优势菌属主要为乳球菌属(Lactococcus)和乳杆菌属(Lactobacillus),其相对丰度分别为(85.13±2.99)%^25.82±1.42%和(4.15±1.38)%^57.21±3.11%;而在属的种类上,LS最多,为409个属,AL最少,为15个属。聚类分析显示,不同曲拉样本的菌群与地理位置存在一定关系,同一个采样区的样本具有一定的聚类趋势,同时发现LZ、RKZ和CD可聚为一类,而其他4个地区的样品较为离散,且各自独立。

Comparative analysis of the bacteria community structure of Qula in different producing areas in Tibet

In order to investigate the bacterial diversity and microbial safety of Qula(traditional fermented dairy products)in different producing areas of Tibet,high-throughput sequencing technology was used to analyze the bacteria diversity and community structure systematically in Qula samples collected from 7 regions including Lhasa(LS),Shigatse(RKZ),Sannan(SN),Changdu(CD),Nyingchi(LZ),Nagqu(NQ),Ali(AL)in Tibet.The results showed that the Qula samples had a high degree of bacterial diversity,and there were certain commonalities and differences in the samples of different regions.Firmicutes and Proteobacteria were the dominant phylum in different samples at the phylum level,and the relative abundance were(12.82±5.63)%-(96.54±1.39)%and(3.46±1.39)%-(75.09±9.37)%,respectively.The type of phylum was up to 24 phyla in Lhasa(LS)sample and 2 in Ali(AL)sample,which was the least.At the genus level,the dominant bacterial genera in LS were Ralstonia,Pseudomonas and Ochrobactrum,and the relative abundance were(17.25±7.05)%,(16.05±3.22)%and(9.52±3.19)%,respectively.While the dominant bacterial genera in the other six regions were Lactococcus and Lactobacillus at the genus level,and the relative abundance were(85.13±2.99)%-(25.82±1.42)%and(4.15±1.38)%-(57.21±3.11)%,respectively.LS samples had a maximum of 409 genera and AL had the least of 15 genera at the genus level.The cluster analysis showed that the diversity and community structure of bacteria in different Qula samples had a certain correlation with the geographical location.The samples in the same sampling area had a certain clustering trend.At the same time,it was found that LZ,RKZ and CD could be clustered into one category,while the other four regions were discrete and independent.