新疆发酵驼乳中分解植酸盐酵母菌的筛选及鉴定

为发掘和保护新疆牧区传统发酵驼乳中潜在益生酵母菌资源，从新疆伊犁地区不同牧区采集12份传统发酵驼乳样品，通过酵母浸出粉胨葡萄糖（YPD）培养基分离酵母菌，通过富含植酸二钾的培养基初筛及降解植酸盐能力的测定从中筛选可降解植酸盐的酵母菌，通过形态观察、生理生化试验及5.8S rDNA ITS1/ITS4区域序列同源性分析进行菌种鉴定，并测定其耐酸及耐胆盐性能。结果表明，筛选出11株可分解植酸盐的酵母菌，鉴定8株为库德毕赤酵母（Pichia kudriavzevii），2株为白地霉（Geotrichum candidum），1株为乳酸克鲁维酵母（Kluyveromyces lactis），其中库德毕赤酵母菌BJ9-12在模拟胃液和模拟肠液中的存活率分别为87.79%和81.50%，耐酸及耐胆盐性能较好，且培养48 h时分解植酸盐的透明圈直径达到3.45 cm，在发酵食品中具有良好的应用潜力。

Screening and identification of phytate-degrading yeasts from fermented camel milk in Xinjiang

A total of 12 traditional fermented camel milk samples were collected from pastoral areas in Yili, Xinjiang, to explore and protect potential probiotic yeast resources of traditional fermented camel milk in Xinjiang pasturing area. The yeasts were isolated by yeast extract peptone dextrose (YPD) medium, and the phytate-degrading probiotic yeasts were screened by preliminary screening with the medium rich in phytic acid dipotassium salt and the phytate-degrading capacities were determined. These yeasts were identified by the cell morphology observation, physiological and biochemical tests, and 5.8S rDNA ITS1/ITS4 regional sequence homology analysis, and the tolerances of acid and bile salt were determined. The results showed that 11 phytate-degrading yeasts were screened and identified, including 8 strains of Pichia kudriavzevii, 2 strains of Geotrichum candidum, and 1 strain of Kluyveromyces lactis. Among them, the P. kudriavzevii BJ9-12 had better acid and salt tolerance, with the survival rate of 87.79% and 81.50% in simulated gastric juice and simulated intestinal juice, respectively. Moreover, the P. kudriavzevii BJ9-12 could form a transparent circle with diameter 3.45 cm after culture 48 h, which had potential application prospects in the fermented food.