基于16S rRNA基因序列分析法比较苏尼特双峰驼和阿拉善双峰驼自然发酵酸驼乳的微生物多样性

Application of 16S rRNA high-throughput sequencing for comparative study of the microbial diversity of traditional fermented bactrian camel milk from Alxa bactrian camel and Sonid bactrian camel

摘要:

[目的]传统发酵乳制品是一类未经任何处理自然发酵而成的，其微生态环境未遭破坏，从而乳酸菌的生物学特性和基因多样性得到了很好的保留，具有开发和利用价值。自然发酵酸驼乳常用来治疗多种疾病且效果良好，与其中丰富的乳酸菌资源有着密不可分的联系。然而，目前有关自然发酵酸驼乳微生物菌群及多样性相关研究甚少。因此进一步挖掘内蒙古地区双峰驼自然发酵酸驼乳微生物群落结构和多样性是至关重要的。[方法]本研究采用Illumina Miseq测序技术，测定了苏尼特和阿拉善双峰驼的自然发酵酸驼乳中微生物16S rRNA V3-V4区序列，并对群落结构和多样性进行了比较分析。[结果]多样性分析表明，苏尼特双峰驼酸驼乳中微生物群落丰富度和种群差异性比阿拉善双峰驼酸驼乳大，细菌多样性也高。在门水平上，苏尼特和阿拉善双峰驼酸驼乳中的菌群均以厚壁菌门（Firmicutes）和变形菌门（Proteobacteria）为主。在属水平上，苏尼特双峰驼酸驼乳主要以乳杆菌属（Lactobacillus）和乳球菌属（Lactococcus）为优势菌群，阿拉善双峰驼酸驼乳以乳杆菌属（Lactobacillus）和醋酸杆菌属（Acetobacter）为优势菌属。此外，肠杆菌属（Enterobacter）、拉乌尔菌属（Raoultella）和明串珠菌属（Leuconostoc）等的含有食源性致病菌和环境污染菌的菌属被检出。综上所述，不同地区不同品种酸驼乳的乳酸菌种类及优势菌群有较大差异，存在显著的地理差异。[结论]通过本研究，不仅对苏尼特和阿拉善双峰驼自然发酵酸驼乳乳酸菌的组成和种类有了明确的认知，为评估发酵酸驼乳微生物群落对消费者身体健康的影响提供了数据基础的同时为今后筛选优势菌群和挖掘新型益生菌奠定基础。

Abstract:

[Objective] Traditional fermented camel milk is a valuable source of food for people living in the arid areas, and it is often used to treat a variety of disease with good effects. Its nutritional and medical functions are closely related to its abundant lactic acid bacteria. However, the studies of bacterial diversity of fermented camel milk are scattered and the amount of available data are still limited. Therefore, it is necessary to explore the microbiota composition and diversity of the traditional fermented camel milk.[Methods] We sequenced the V3-V4 region of 16S rRNA genes in fermented camel milk of Alxa and Sonid Bactrian camel by Illumina Miseq platform, and the microbiota composition and diversity were compared and analyzed.[Results] The results of Alpha diversity showed that the fermented camel milk from Sonid has higher bacterial diversity and microbial community richness than those of Alxa. At the phylum level, Firmicutes and Proteobacteria were dominant in both of them. At the genus level, Lactobacillus and Lactococcus were dominant in Sonid samples, Lactobacillus and Acetobacter were dominant in Alxa samples. In addition, we also found some foodborne pathogens and environmentally contaminating bacteria, such as Enterobacter, Raoultella and Leuconostoc. There were significant differences in the types and dominant bacteria in fermented camel milk in different regions. [Conclusion] These results provide insights into the microbiota community and diversity of traditional fermented camel milk, and also lay the foundation for screening dominant bacteria and excavating new probiotics in the further studies.