自然发酵乳及传统开菲尔粒中酵母菌的多样性研究

Biodiversity of yeast in natural fermented dairy and the traditional Kefir grain

研究自然发酵乳和内蒙古牧区传统开菲尔粒中酵母菌的多样性,目的是探寻酵母菌的主要菌群和种属类型,为筛选可发酵低酒度发酵乳的酵母菌奠定基础。该研究首先进行稀释涂布和划线分离出酵母菌株、然后进行菌落形态和细胞形态的初步分类,再进行5.8SrDNA-ITS区域RFLP分子鉴定,将分离到的130株酵母菌区分为10种形态类型、6种分子类型,分别为马克思克鲁维酵母菌(Kluyveromyces marxianus)、隐球酵母菌(Cryptococcus sp.)、酿酒酵母菌(Saccharomyces cerevisiae)、热带假丝酵母菌(Candida tropicalis)、陆生伊萨酵母菌(Issatchenkia terricola)和季也蒙毕赤酵母菌(Pichia guilliermondii)。其中马克思克鲁维酵母菌、酿酒酵母菌和季也蒙毕赤酵母菌为优势菌群,具有酿造低酒度发酵乳的潜力。

Biodiversity of yeast in natural fermented dairy and traditional kefir grain from Inner Mongolia was investigated.The purpose was to explore the main microflora and yeast species,laying the foundation for selecting yeast which can ferment low alcohol degree dairy.Yeast strains were isolated by gradient diluting and streaking plates,and then classified preliminarily according to colony morphology and cell morphology,followed by 5.8S rDNA-ITS restriction fragment length polymorphism （RFLP） analysis,130 selected yeast strains were divided into 10 phenotypes and 6 molecular types.The species identified by 5.8S ITS-RFLP corresponded to Kluyveromyces marxianus,Cryptococcus sp.,Saccharomyces cerevisiae,Candida tropicalis,Issatchenkia terricola and Pichia guilliermondii.Among them,K.marxianus,S.cerevisiae and P.guilliermondii were the dominant species,which had the potential for fermenting low alcohol degree dairy.