西藏传统发酵牦牛酸奶中乳酒假丝酵母的分离鉴定与系统发育学分析  

Isolation, identification and phylogenetic analysis of Candida kefyr in traditional fermented yak yoghurt in Tibet

作　　者：魏超[1,2] 毛建霏 代晓航 郭灵安[2] WEI Chao;MAO Jian-Fei;DAI Xiao-Hang;GUO Ling-An(Analysis and Determination Center of Sichuan Academy of Agricultural Sciences,Chengdu 610066,China;Agrieultural Product Quality and Safety Risk Assessment Laboratory of Ministry of Agriculture (Chengdu),Chengdu 610066,China)

机构地区：[1]四川省农业科学院分析测试中心,成都610066 [2]农业部农产品质量安全风险评估实验室(成都),成都610066

出　　处：《食品安全质量检测学报》2019年第3期576-582,共7页Journal of Food Safety and Quality

基　　金：国家奶产品质量安全风险评估重大专项(GJFP2017008)~~

摘　　要：目的开发西藏传统发酵牦牛酸奶的微生物种质资源。方法对拉萨周边牧场的10份传统发酵牦牛酸奶样品进行乳酸菌的分离过程中得到6株酵母菌,通过常规形态特征、生化和基质解吸电离飞行时间质谱法(matrix desorption ionization time-of-flight mass spectrometry, MALDI-TOF-MS)进行鉴定,对其质谱标识峰进行蛋白质水平同源性分析,采用ITS序列对其进行基因学比对。结果经生化和质谱鉴定分离的6株酵母为乳酒假丝酵母,分离酵母和已知乳酒假丝酵母通过ITS序列在GENEBANK比结果为命名有差异为马克斯克鲁维酵母,但乳酒假丝酵母可认定为其无性型变种。蛋白质同源分析结果表明6株分离菌与已知乳酒假丝酵母在蛋白质水平有一定差异,收集到其特征性蛋白质片段的标识峰12组。结论乳酒假丝酵母的分离与研究为西藏传统发酵牦牛酸奶中酵母菌的开发提供理论支撑。Objective To develop the microbial germplasm resources of traditional Tibetan yak yoghurt. Methods A total of six strains of yeast were obtained from the isolation of lacticacid bacteria from 10 traditional fermented yak yoghurt samples in pastures around Lhasa. The morphological characteristics, biochemical identification and matrix desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS) were used to identify the protein-level homology analysis of the mass spectrometric peaks, and ITS sequences were used for genetic comparison. Results The six strains of isolated yeast were all identified by biochemical and mass spectrometry as Candida kefyr. The isolated yeast and Candida kefyr were identified as different Kluyveromyces marxianus by ITS sequence in GENEBANK, but Candida kefyr could be identified as an asexual variant. The results of protein homology analysis showed that the 6 isolates were different from the known Candida lactis at the protein level, and 12 peaks of the characteristic protein fragments were collected. The results of protein homology analysis showed that there was a certain difference in protein level between the 6 isolates and Candida kefyr. The identification peaks of characteristic protein fragments were collected in 12 groups. Conclusion The isolation and research of Candida lactobacillus provides theoretical support for the development of yeasts in traditional yak yoghurt fermentation in Tibet.

关 键 词：西藏传统发酵牦牛酸奶 乳酒假丝酵母 马克斯克鲁维酵母 基质解吸电离飞行时间质谱法 ITS系统发育分析 

分 类 号：TS252.54[轻工技术与工程—农产品加工及贮藏工程]