宏基因组学探究原料乳冷藏过程菌群变化规律  

Metagenomics approach to explore the changes of bacterial community in raw milk during refrigerated storage

作　　者：王媛媛[1] 剧柠[1] 苟萌 罗玉龙 李璞钰 Wang Yuanyuan;Ju Ning;Gou Meng;Luo Yulong;Li Puyu(College of Food and Wine,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学食品与葡萄酒学院,银川750021

出　　处：《农业工程学报》2020年第22期333-340,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(31760479)。

摘　　要：为探究原料乳4℃冷藏期间细菌群落的变化规律,该研究使用Illumina Hiseq测序平台,对原料乳冷藏期间微生物变化及功能注释进行宏基因组学分析。结果表明:随着冷藏时间的延长,原料乳中的微生物在数量和种群构成上均发生了显著改变。冷藏72 h期间,优势菌群由不动杆菌属、链球菌属、无浆体属和梭菌属向黄杆菌属、假单胞菌属和乳球菌属逐渐演替。功能注释结果显示:复制重组修复、翻译/核糖体结构与生物发生、细胞壁/膜的生物发生、脂质代谢在冷藏前期相对丰度较高。氨基酸、碳水化合物的转运与代谢在冷藏后期相对丰度较高。其中脂质代谢与不动杆菌属显著相关(P<0.001),氨基酸代谢、碳水化合物代谢与假单胞菌属显著相关(P<0.01)。研究表明冷藏原料乳中不动杆菌属及假单胞菌属对乳成分影响较大。通过控制冷藏原料乳有害微生物繁殖,能够维持乳成分稳定。研究结果可为生鲜乳保藏、液态乳灭菌控制、奶酪加工等提供理论依据。Refrigeration storage is one of the important methods to inhibit the reproduction of microorganisms in raw milk.But the psychrophilic bacteria still grow during this time,particularly on synthesizing phospholipids at the relatively low storage temperature.Meanwhile,these psychrophilic bacteria hydrolyze protein and fat can cause discoloration,odor,viscosity increase,gelation,rancidity,and other defects phenomena in the raw milk.So far,there are few reports on the changes of the flora in the raw milk during cold storage.In this study,an IlluminaHiseq sequencing platform was established to conduct metagenomic analysis of bacteria in the raw milk,in order to investigate the bacterial community succession and functional characteristics of raw milk with the extension of refrigeration time.During 72 hours of storage,the number of culturable microorganisms observably increased in the raw milk,including the number of colonies,psychrophilic bacteria,lactic acid bacteria,and coliform bacteria.Taxonomy annotation indicated that there was a significant effect for the microbial succession of raw milk during cold storage.At the genus level,the dominant flora gradually evolved from Acinetobacter,Streptococcus,Anaplasmaand and Clostridium to Flavobacterium,Pseudomonasand Lactococcus.At the species level,it evolved from Acinetobacter sp.TTH0-4,Anaplasmaphagocytophilum,Streptococcus pneumoniae,and Streptococcus mutans to Flavobacteriumfrigidarium,Pseudomonas fluorescensand Lactococcuspiscium.There were few reports on Acinetobacter sp.TTH0-4,Flavobacteriumfrigidarium,and Lactococcuspiscium.The results of COG functional annotation showed that the L(replication,recombination and repair),J(translation,ribosomal structure and biogenesis),M(cell wall/membrane/envelope biogenesis)had relatively higher abundance in the early stage of refrigeration(24 h),suggesting that the raw milk microbes were more resistant to the variable milk environment during this period.The relative abundance of E(Amino acid transport and metabolism)and G(Carbohyd

关 键 词：原料乳 冷藏 宏基因组学 菌群演替 功能注释 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]