云南阳宗海酵母菌种群结构及产胞外酶测试

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

摘要:

摘要:【目的】研究阳宗海酵母菌种群结构，分析生物因子及非生物因子对酵母菌种群分布的影响;测试阳宗海酵母菌产胞外酶活性。【方法】水样用醋酸纤维素滤膜过滤，原位培养分离酵母菌;梯度稀释法分离土样和底泥样品;对分离得到的菌株进行DNA 提取和测序，分析26S rDNA的D1/D2区域，并结合形态及生理生化指标进行鉴定;用产酶筛选培养基对分离得到的酵母菌进行产胞外酶活性测试。【结果】共分离得到201株酵母菌，鉴定分属于15个属48个种，其中包括10个潜在的新种;普鲁兰类酵母(Aureobasidium pullulans)，库德里阿兹威氏毕赤酵母(Pichia kudriavzevii)，胶红酵母(Rhodotorula mucilaginosa)，Cryptococcus podzolicus 是优势种;15.9%的酵母菌具有产胞外酶活性，主要是脂肪酶和淀粉酶。【结论】阳宗海酵母菌有较为丰富的多样性，人为活动对阳宗海酵母菌分布影响较大，其次浊度、电导率也是影响酵母菌种群分布的重要因素;阳宗海产胞外酶酵母菌可能参与湖泊生态系统的自然循环。

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．