云南星云湖酵母菌多样性及产类胡萝卜素的评价

Diversity and evaluation of carotenoids-producing of yeasts isolated from Xingyun Lake

【背景】星云湖属云南高原湖泊,对其酵母菌的多样性研究和产类胡萝卜素菌株的筛选有助于开发利用星云湖酵母菌资源。【目的】研究云南星云湖酵母菌群落结构多样性,筛选和评价产类胡萝卜素活性菌株。【方法】采用膜过滤平置培养对星云湖水样进行酵母菌分离;应用26S rRNA D1/D2区域序列分析和形态特征及生理生化指标相结合,对分离获得的酵母菌进行鉴定;运用软件BIO-DAP分析酵母菌类群的多样性;采用酸热法提取类胡萝卜素,紫外分光光度计测定类胡萝卜素含量。【结果】从星云湖湖水中分离得到797株酵母菌,鉴定为18个属37个种。胶红酵母(Rhodotorula mucilaginosa)和Naganishia albida是优势种,分别占总菌株数的36.64%和28.86%;有28株酵母菌类胡萝卜素产量可达200μg/g细胞干重以上;有4株类胡萝卜素产量可达300μg/g细胞干重以上;粘红酵母(Rhodotorula glutinis) 2株、胶红酵母(Rhodotorula mucilaginosa)和Rhodosporidiobolus fluviale各1株。【结论】云南高原湖泊星云湖的酵母菌具有丰富的多样性,湖泊的营养化程度以及地理差异影响酵母菌群落的结构;红冬孢酵母属(Rhodosporidiobolus)和红酵母属(Rhodotorula)是星云湖类胡萝卜素产量可达300μg/g细胞干重以上的主要类群。有进一步开发研究的价值。

[Background] Xingyun Lake is one of plateau lakes of Yunnan. The study of its diversity of yeasts and the screening of carotenoids-producing strains contribute to the development and utilization of the yeast resources of Xingyun Lake.[Objective] To study the diversity of community structure of yeasts in Xingyun Lake, and to screen the carotenoids-producing strains.[Methods] Yeast separation was carried to on the water samples of Xingyun Lake by membrane filtration flat culture. Identification was based on sequence analysis of D1/D2 domains of 26 S rRNA gene, and to combinate with morphological characteristics and physiological and biochemical indicators, and the diversity of yeast was analyzed by software BIO-DAP. The carotenoids were extracted by acid-heating method, and the content of carotenoids were determined by ultraviolet spectrophotometer.[Results] A total of 797 strains were isolated from the water samples of Xingyun Lake, and identified as 18 genera and 37 species. The Rhodotorula mucilaginosa and Naganishia albida are the dominant species, accounting for 36.64% and28.86% of the total strains, respectively. There were 28 strains of yeast carotenoids with a yield of more than 200 μg/g cell dry weight, and 4 strains of carotenoeds-producing were up to 300 μg/g cell dry weight:Rhodotorula glutinis(2 strains), Rhodotorula mucilaginosa(1 strain) and Rhodosporidiobolus fluviale(1 strain).[Conclusion] The yeasts of Xingyun Lake are rich in diversity, and the degree of lake nutrition and geographical difference affect the structure of yeast community. In Xingyun Lake, Rhodosporidiobolus and Rhodotorula are the major groups of carotenoids-producting, and carotenoids-producting were up to300 μg/g of cell dry weight. It has the value of further development research.