单分子实时测序技术研究不同来源原料乳中群落组成及多样性

Analysis of bacterial community composition and diversity in raw milk from different sources using single molecule real time sequencing

中文关键词:  单分子实时测序  原料乳  细菌组成  功能预测

英文关键词:single molecule real time sequencing  raw milk  bacterial composition  function prediction

中文摘要:

      目的 采用三代单分子实时测序法(single molecule real time sequencing, SMRT)研究北京和内蒙古两地原料乳中的细菌群落组成及多样性, 解析其携带污染菌的差异, 为原料乳质量及风险评估提供基础数据。 方法 收集北京和内蒙古两地春夏季和秋冬季的原料乳样品20份, 采用SMRT技术对其进行基于16S rDNA基因全长的测序和多样性分析。在此基础上, 对其进行了微生物相关功能性预测。结果 不同产地与不同采样季节原料乳中细菌群落的结构组成和相对丰度存在差异, 假单胞菌属、不动杆菌属与乳球菌属是大部分样品中相对丰度最高的细菌, 其中脆弱假单胞菌的相对丰度与原料乳冷链运输时间正相关。功能预测揭示了原料乳脂肪质量可能具有地区差异性, 维生素与氨基酸质量可能具有季节差异性。结论 两产地原料乳菌群分析结果提示了原料乳潜在的食品安全风险, 并且除致病菌风险之外耐药菌及耐药基因传播的风险同样不容忽视; 此外, 乳球菌属细菌具有开发作为益生菌的潜力。本研究结果为原料乳的质量安全监测评估和功能菌种挖掘提供了参考依据。

英文摘要:

      Objective To study the bacterial community composition and diversity in raw milk collected in Beijing and Inner Mongolia use the three-generation single molecule real time sequencing (SMRT) technology, and analyze the difference in raw milk samples carrying contaminated bacteria to provide basic data for raw milk quality and risk assessment. Methods A total of 20 raw milk samples collected from Beijing and Inner Mongolia in spring, summer, autumn and winter were sequenced based on the full length of 16S rDNA gene and analyzed for diversity using SMRT technology. On this basis, the microbial-related functional predictions were carried out. Results There were differences in the structural composition and relative abundance of bacterial communities in raw milk from different provinces and different sampling seasons, Pseudomonas, Acinetobacter and Lactococcus were the bacteria with the highest relative abundance in most samples, and the relative abundance of Pseudomonas fragilis was positively correlated with the cold chain transit time of raw milk. Functional prediction revealed that the quality of raw milk fat may had regional differences, and the quality of vitamins and amino acids may have seasonal differences. Conclusion The results of the analysis of the raw milk flora in the 2 provinces indicate the potential food safety risks of raw milk, and the risk of drug-resistant bacteria and the spread of drug-resistant genes in addition to the risk of pathogenic bacteria should also not be ignored, furthermore, Lactococcus bacteria have the potential to develop as probiotics. The results of this study provide references for the quality and safety monitoring of raw milk and the excavation of functional strains.