Yeasts from Yangzonghai Lake in Yunnan (China):diversity and extracellular enzymes

Abstract:

Abstract:［Objective］The aims of this study were to investigate yeast diversity in Yangzonghai Lake，and to explore the value of these yeasts in such ecological environment，and at the same time，to analyze biological factors and abiotic factors on the influence of the yeast diversity．［Methods］Water was filtered through cellulose acetate membrane，serial dilutions of soil and sediment; The D1/D2 domain of 26S rRNA gene of all yeast strains have been sequenced and analyzed．The ability of the yeast strains to produce various enzymes was tested by enzyme screening plates．［Results］In total of 201 yeast strains were isolated，these strains were identified as 48 species in 15 genera，including 10 presumed new species or variety; 15.9% showed at least one extracellular enzymatic activity，mainly the lipases and amylases．［Conclusion］The yeast community from Yangzonghai Lake showed high species richness，and anthropogenical influenced is an important factor for the yeast count and distribution，at same time，conductivity and turbidity are also important factors for yeast distribution; Some yeasts produced at least one extracellular enzymatic activity，which suggested that these microorganisms are participating in nature cycle and are metabolically active in the lake．

Key words:Keywords: Yongzonghai lake，yeast diversity，environmental factors，extracellular enzymatic