Isolation And Identification Of Wine-Related Yeast From East Foot Of Helanshan Mountains Of Ningxia

Yeasts are the main microorganisms, which play a significant role during vinification. But at the present time, the entire dependence on imported wine yeasts in Chinese wine industry lead to the homogenization of wine quality. The ecological conditions of northwest region are complex, varied and rich in yeast resources. The extensive application of imported dry yeasts results in degeneration of variation of yeasts and weakening the role of indigenous yeasts. It also threatens yeast resources in our country. As a result of which, research and protection of local yeast resources is necessary to carry out.Ningxia is one of the most promising quality areas for viticulture and wine production, which owns the unique climate and geographic circumstance. The aim of this study is to discover the wine related yeasts resources and diversity in Ningxia, and to explore the yeast germplasm with Chinese characteristics, which provides supports to study, use and breed wine yeasts, to improve the problem of homogenization of wine quality, and to increase the international competition of Chinese wine.In this study, 552 yeast strains were collected from wine district of East foot of Helanshan Mountains. These wine yeasts were identified by analysis of morphological observation and WL Nutrient Medium. There are 7 types of 125 yeast strains collected from Yinguangxia third vineyard. 264 yeast strains collected from Imperial Tombs of Western Xia vineyard were classified into 5 types and 163 yeast strains from Yuquanying vineyard were classified into 6 types. By using the analysis of 26S rRNA gene D1/D2 domain sequences and 5.8S-ITS region sequences, eight genus and ten yeast species were identified in East Foot of Helanshan Mountains of Ningxia, including: Saccharomyces cerevisiae, Zygosaccharomyces bailii, Hanseniaspora occidentalis, Pichia kluyveri, Metschnikowia pulcherrima, Issatchenkia orientalis, Hanseniaspera uvarum, Hanseniaspora vineae, Cryptococcus magnus, Candida zemplinina. Among them, Saccharomyces cerevisiae, Zygosaccharomyces bailii, Hanseniaspora occidentalis, Pichia kluyveri, Metschnikowia pulcherrima, Issatchenkia orientalis, Hanseniaspera uvarum were the species isolated from Yinguangxia third vineyard. The strains isolated from Imperial Tombs of Western Xia vineyard belonged to four species: Saccharomyces cerevisiae, Candida zemplinina, Issatchenkia orientalis and Hanseniaspera uvarum. The isolates from Yuquanying vineyard belonged to five species: Saccharomyces cerevisiae, Hanseniaspora vineae, Hanseniaspera uvarum, Cryptococcus magnus and Candida zemplinina.H. uvarum, H. occidentalis and S. cerevisiae were the dominant species in Yinguangxia third vineyard, accounted for 16.8%, 16.8% and 56.8% respectively; In Imperial Tombs of Western Xia vineyard, the largest quantity of yeast species were I. orientalis, H. uvarum and S. cerevisiae, accounted for 17.63%, 58.99% and 20.14% respectively; While C. zemplinina, H. uvarum, S. cerevisiae were the main species in Yuquanying vineyards, accounted for 21.19%, 31.8% and 45.03% respectively. H. uvarum and S. cerevisia were more extensive adaptive yeast species.The change tendency of the yeasts' community about three regions is consistent. H. uvarum was the dominated species in the early stage of spontaneous fermentation. Then non-Saccharomyces yeasts were later replaced by S. cerevisiae, which dominated towards the end stage of spontaneous fermentation. However, the dynamics of non-Saccharomyces yeast populations and their appearance during the spontaneous fermentation were different.