纳木错夏季酵母菌多样性及其影响因素

以纳木错湖水为研究对象，采用膜过滤平置培养法分离纯化酵母菌，并结合ITS区域序列分析与经典分类法对酵母菌菌株进行鉴定，运用生物信息学和统计学方法分析水体可培养酵母菌的多样性及其与理化因子之间的相关关系.结果显示，从纳木错水体中分离出1067株酵母菌，分属于27个属45个种及2个潜在新分类单元，优势种为Vishniacozyma victoriae和Naganishia adeliensis.NMDS分析显示，纳木错不同区域水体可培养酵母菌群落β多样性差异明显.Pearson相关性分析结果表明，酵母菌总丰度与pH值、电导率、总溶解固体量、盐度呈极显著负相关（P<0.01），与总氮、氨氮呈显著正相关（P<0.05）；物种数、Shannon-Wiener多样性指数、Simpson多样性指数均与总磷呈显著负相关（P<0.05）.冗余分析显示，pH值是影响纳木错水体酵母菌种群分布的主要理化因子.综上，纳木错水体酵母菌资源比较丰富且存在明显的空间异质性，水体理化因子对纳木错水体可培养酵母菌的分布有较大的影响.

Analysis on yeast diversity and the influencing factors during summertime in Nam Co Lake

Yeasts were isolated by membrane filtration flat culture from Nam Co Lake. Identifications of the yeasts were based on sequence analysis of the ITS region, combined with traditional classification method. Moreover, bioinformatical and statistical methods were used to determine the correlationships between diversity of culturable yeast and environmental factors. The result showed that a total of 1067 yeast isolates were identified, belonging to 27 genera and 45 species, and including two previously undescribed taxa. Among them, Vishniacozyma victoriae and Naganishia adeliensis were the dominated species. Furthermore, NMDS analysis showed that the β diversity of the culturable yeast communities in different sites of Nam Co Lake was significantly different. Statistical analysis indicated that the richness of culturable yeast were negatively correlated to lake pH, electric conductivity (EC), and total dissolved salt (TDS). Meanwhile, the richness was positively correlated to total nitrogen (TN) and ammonia nitrogen (NH₃-N). Additionally, the number of yeast species, Shannon-Wiener index, and Simpson index were negatively correlated to total phosphorus (TP). Interestingly, pH played a crucial role in the formation of yest community structures in Nam Co Lake. As a whole, the yeast community in Nam Co Lake showed high species richness, and the community structures differed in different sites, influenced by a variety of environmental factors.