天山冻土中嗜冷酵母菌生物多样性

Diversity of Psychrotrophic Yeast from Permafrost Soil at the Terminus of a Glacier in the Tianshan Mountains

采用麦芽浸膏富集平板涂布天山冻土中可培养酵母菌,通过麦芽浸膏分离培养基筛选菌株。采用酵母菌常规生理生化实验、最适生长温度、最适pH对分离菌株的生理学进行研究。以NL1和NL4为PCR扩增引物,通过26S rRNA基因D1/D2区序列同源性分析,初步确定酵母菌株的系统进化地位。分离筛选到4株嗜低温酵母菌,分属于隐球酵母(Cystofilobasidium infirmominiatum)、掷孢酵母(Sporobolomyces patagonicus)、棒孢酵母(Clavispora lusitaniae)和毕赤酵母(Pichia kluyveri)。

The objective of this study was to investigate the diversity of cuhurable yeast strains from permafrost soils at the terminus of a glacier in the Tianshan Mountains was investigated. Isolation and molecular phylogenetic analysis were performed in order to expand our knowledge on diversity of psychrotrophic and psychrophilic yeast. In addition, efforts focused on screening for psychrophilic yeast. Psychrophilic yeast strains were detected on YEPG plates ,respectively. Identity and genetic diversity of strains isolated was determined by 26S rRNA gene D1/D2 by the forward primers NL1 and the reverse NIA. The physiological tests were carried out to determine the phonotypic differences between strains showing high similarity of 26S rRNA gene sequences. In all,4 yeast stains was isolated by 26S rRNA gene D1/D2 and internal transcribed spaeers of 4 genera （Cryptoeoceus,Sporobolomyees,Clavispora,Piehia）. The results enrich our knowledge on the differences of psychrotrophic yeast diversity between the glacier under study and other worldwide cold habitats are also discussed.