Wang Hao, Wang Cuina, Guo Mingruo
Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China; Department of Nutrition and Food Sciences, College of Agriculture and Life Sciences, University of Vermont, Burlington, VT 05405, USA.
Food Res Int. 2020 Dec;138(Pt B):109784. doi: 10.1016/j.foodres.2020.109784. Epub 2020 Oct 16.
Kefir grains are a unique symbiotic association of different microbiota, including a variety of bacterial and fungal species. The microbiota in kefir grains is strongly influenced by the geographical origin and sub-culturing environment. After sub-culturing in goat milk for 2 to 4 months, amplicon sequencing (16S rRNA and ITS1 region) was applied for the identification of bacterial and fungal autogenic succession of three kefir grains collected from China (CN, Asia), Germany (DE, Europe) and United States of America (USA, America). Taxonomic analysis displayed three main bacterial and fungal species in kefir grains from different origins during sub-culturing process (Lactobacillus helveticus, Lactobacillus kefiranofaciens and Lactobacillus kefiri for bacteria, Kazachstania unispora, Kluyveromyces marxianus and Saccharomyces cerevisiae for fungi). Based on the results of beta diversity analysis, microbiota in kefir grains from CN and DE would be stable when sub-cultured in goat milk for more than three months. Differently, a highly microbial stability has been found for the sample from USA during the whole sub-culturing process. These results helped to understand the composition and stability of microbiota in kefir grains when sub-cultured in goat milk.
开菲尔粒是不同微生物群的独特共生组合，包括多种细菌和真菌物种。开菲尔粒中的微生物群受到地理来源和继代培养环境的强烈影响。在山羊奶中继代培养2至4个月后，应用扩增子测序（16S rRNA和ITS1区域）来鉴定从中国（CN，亚洲）、德国（DE，欧洲）和美国（USA，美洲）收集的三种开菲尔粒的细菌和真菌自生演替情况。分类学分析显示，在继代培养过程中，来自不同来源的开菲尔粒中有三种主要的细菌和真菌物种（细菌为瑞士乳杆菌、开菲尔糖酸乳杆菌和开菲尔乳杆菌，真菌为单孢哈萨克酵母、马克斯克鲁维酵母和酿酒酵母）。基于β多样性分析结果，当在山羊奶中继代培养三个月以上时，来自中国和德国的开菲尔粒中的微生物群将保持稳定。不同的是，在整个继代培养过程中，美国的样品具有高度的微生物稳定性。这些结果有助于了解开菲尔粒在山羊奶中继代培养时微生物群的组成和稳定性。
