In this paper , thirty strains of yeast were isolated from nineteen samples of fermented milk ( ten koumiss samples , three fermented goat milk samples , four fermented milk samples , two shubat samples ) which were collected from the west - centre region of inner mongolia from which we aimed to select the yeast with high vitalistic ? galactosidase . according to the results of dedermination that were the metabolism rate and ratio vitality of ? galactosidase , stk - 1 - 1 has been selected . the result of identification showed that stk - 1 - 1 belonged to kluyveromyces marxianus of kluyveromyces 本研究主要以内蒙古中西部地区牧区采集的19个发酵乳样品（ 10份酸马奶、 3份发酵山羊奶、 4份酸牛奶和2份发酵驼奶）为研究对象，分离获得30株酵母菌，从中筛选乳糖酶高活力酵母菌株。根据乳糖代谢率和乳糖酶比活力的测定结果，选出菌株stk - 1 - 1为优胜菌株。经鉴定，该菌株属克鲁维酵母属（ kluyveromyces ）的马克斯克鲁维酵母（ kluyveromycesmarxianus ） 。
