新疆地区酸马奶中酵母菌的鉴定及其生物多样性分析

Identification and biodiversity of yeasts isolated from Koumiss in Xinjiang of China

摘要:

从新疆少数民族牧民家庭采集的28份传统工艺酿造酸马奶样品中分离出87株酵母菌,并对其进行了生理生化鉴定、分子生物学鉴定和生物多样性分析。生化试验结果表明,新疆地区酸马奶中的酵母菌为Saccharomyces unisporus(占总分离株的48.3%),Kluyveromyces marxianus(27.6%),Pichia membranaefaciens(15.0%)和Saccharomyces cerevisiae(9.2%)。选取其中的6株酵母菌和1株参考菌株,进行大亚基(26S)rDNA D1/D2区域(600bp左右)碱基序列分析,并通过GenBank进行同源序列搜索以确定各菌株的归属,进一步验证生理生化方法的正确性。从得到的结果中可以看出,S.unisporus和K.marxianus为新疆地区酸马奶中的优势菌。

Abstract:

A total of 87 yeast strains were isolated from 28 home-made koumiss samples，a traditional fermented mare milk product in Xinjiang of China. The isolates were identified by standard physiological and biochemical tests and analysis of the large-subunit (26S) rDNA gene D1/D2 domain sequences. They are proved to be Saccharomyces unisporus (48.3% of the isolates)，Kluyveromyces marxianus (27.6%) and Pichia membranaefaciens (15.0%)，Saccharomyces cerevisiae (9.2%). Among them，six isolates and a standard yeast strain were selected for analysis of D1/D2 domain sequences. They are indicated as S. unisporus，K. marxianus，S. cerevisiae，P. membranifaciens，P. fermentans，P. galeiformis and the standard yeast strain is indicated as K. lactis (100%). The results obtained demonstrate the value of using analysis of D1/D2 domain sequences methods，in conjunction with the traditional taxonomic methods based on phenotypic characteristics. This study forms an essential step towards the preservation and exploitation of the hidden oenological potential of the wealth of yeast biodiversity of the koumiss in Xinjiang Province. The result obtained shown that S. unisporus and K. marxianus were the predominant strains of koumiss in Xingjiang of China.