天山一号冰川产蛋白酶酵母菌的筛选及其系统发育分析

Screening and Phylogenetic Analysis of Yeast Producing Protease from Permafrost of the Glacier No.1 in the Tianshan Mountains

[目的]筛选天山一号冰川底部沉积层耐低温的产蛋白酶菌株,研究其生理生化特性并做系统发育分析。[方法]以天山一号冰川底部沉积层中耐低温产蛋白的酵母菌株为材料,用Yeast Extract Peptone Dextrose Medium（YPD）培养基活化60株酵母菌;再用选择性培养基筛选产蛋白酶的菌株,观察菌落形态;测定产酶菌株最适温度;最后基于26S r DNA基因D1/D2区序列进行系统发育分析。[结果]从60株酵母菌中共筛选出10株产蛋白酶菌株,其中产酶优势菌为BCY-8、BCY-20,产酶酵母细胞平均大小为2.60~5.00μm,最适生长温度为24℃。经系统发育分析可知,10株产酶酵母菌属于隐球菌（Cryptococcus）、红酵母属（Rhodotorula）、南极酵母（Antarctic yeast）、Uncultured fungus、Mazocraeoides gonialosae。[结论]研究可为低温蛋白酶生物技术的研发奠定基础。

[ Objective ] This research was to isolate cold-adapted protease-producing strains of yeasts from permafrost of the Glacier No. 1 in the Tianshan Mountains, study their physiological and biochemical characteristics, conduct phylogeny analysis. [ Method ] YPD was used to select yeast producing protease, which were identified through the hydrolysis circle. Then, the optimum temperature of the strains and phyloge- netic position determined by the 26S rDNA D1/D2 sequences was studied. ~ Resuh~ 10 isolates were cold-adapted protease-producing strains. The average size of cells were 2.60 to 5.00 ~m and the optimum growth temperature was 24 ~C. Phylogenetic analysis showed that the 10 strains of yeast belonged to Cryptococcu, Rhodotorula, Antarctic yeast, Uncultured fungus and Mazocraeoides gonialosae. [ Conclusion ] The study can lay a foundation for research and development of low-temperature protease.