Yeast Diversity In Nan Dough Processed By Traditional Fermentation In Xinjiang

The yeasts in traditionally fermented Nan dough collected from Urumqi, Aksu,Kashgar and Hotan city of Xinjiang were isolated and identified. After that the diversity of yeasts and evolution of the dominant groups were analyzed. Results preliminary clarified the distribution and diversity of the yeasts in tradition Nan dough and provide useful information for further utilization of yeasts in traditional fermented Nan dough.The counts of yeast in Nan dough samples collected from Xinjiang Urumqi,Aksu, Kashgar and Hotan city were ranged from5.34×105CFU/g to 8.22×105CFU/g,the total number of yeast mainly distributed in 105 CFU / g.A total of 176 yeast strains with different colony characters were isolated from traditional fermented Nan dough sample. They were identified using the 26 S rDNA D1/D2 domain region sequences method. The result was including Saccharomyces cerevisiae for 82 strains(46.59%), Candida humilis for 22 strains(12.5%), Pichia fermentans for 23 strains(13.07%), Pichia membranifacies for 16 strains(9.09%),Hanseniaspora uvarum for 11 strains(6.25%), Torulaspora delbrueckii for 7 strains(3.97%), Wickerhamomyces anomalus for 6 strains(3.41%), Cladosporium ramotenellum for 2 strains(1.14%), Pichia kudriavzevii for 2 strains(1.14%), Pichia anomala for 2 strains(1.14%), Saccharomyces servazzii for 1 strain(0.57%),Cryptococcus albidus for 1 strain(0.57%), Kodamea ohmeri for 1 strain(0.57%), 10 genera 13 Species.Yeast diversity in Nan dough from four different regions of Xinjiang showing differences, Hotan has the highest yeast diversity; Aksu has the largest number of yeast isolates, yeast diversity lower than Hotan, yeast groups in that two regions are similar; isolates from Urumqi belonging to four genera four species; Kashgar has the larger number of yeast isolates, but they belong to two genera four species.Among these 176 isolates, a total of 82 strains were belong to Saccharomycescerevisiae, most widely distributed in four different area, representing 46.59% of all isolates, and which are the dominant group in Xinjiang Nan dough.In the phylogenetic tree, the Saccharomyces cerevisiae formed two big and five small branches, among them, A1 branch constituted by 75 strains and were the most adaptable, the most widely distributed, the highest differentiation degree and the most predominant strains of Nan dough fermentation, plays a key role in the process of Nan dough fermentation.