Identification Of Yeast Species And Genetic Diversity Of Saccharomyces Cerevisiae From Penglai,Shandong

Different viticultural region are characterized by a high diversity of yeast species and different strains,suggesting the occurrence of natural specific strains associated with particular terroir.The large-scale utilization of active dry yeast(ADY)has a great impact on the diversity of local yeast populations,with the loss of a patrimony of yeast biodiversity once typical of the areas.Studying the yeast diversity can shed light on their population dynamics,lead to the discovery of strains with novel enological characteristics of industrial value and help produce wines typical of specific areas.The evolution of yeast species and S.cerevisiae genotypes during fermentations of nine varieties in 2012 and 2013 in Penglai,Shandong region of China were followed in this study.Using a combination of colony morphology on Wallerstein Nutrient(WLN)medium,sequence analysis of the 26S rDNA D1/D2 domain and interdelta sequence fingerprinting analysis,a total of 3383 isolates were identified at the species level.The main results are as follows:1.The isolates isolated from Chardonnay and Cabernet Sauvignon have 37 types on WLN medium belonged to 17 species of 12 genera,namely,Saccharomyces cerevisiae.Hanseniaspora uvarum,Sporidiobolus pararoseus,Meyerozyma guilliermondii,Issatchenkia terricola,Cryptococcus magnus,Aureobasidium pullulans,Pichia aff.fermentans,Saccharomycopsis fibuligera,Pichia occidentalis,Wickerhamiella domercqia,Hanseniaspora opuntiae,Pichia kluyveri,Saccharomycodes ludwigii,Candida zemplinina,Wickerhamiella sp.,Cryptococcus sp.,with proportion of 40.5%,31.4%,2.3%,1.9%,8.8%,0.4%,3.4%,1.8%,0.2%,1.5%,0.2%,0.5%,1.8%,0.3%,3.7%,0.2%,0.3%.2.The total of 538 S.cerevisiae isolates were isolated in the spontaneous fermentation in eight varieties in 2012.Total of 82 genotypes of S.cerevisiae were distinguished by interdelta sequence analysis among these strains,the number of the genotypes in the fermentation of Chardonnay,Cabernet Sauvignon,Riesling,Merlot,Cabernet Franc,Petit Manseng,Marselen and Tannat is 18,3,6,16,11,16,9 and 6,respectively.ER-17,CA,GA-22,LC-30,PB-43,IB-54,MH-74 and TA-77 is the dominant genotypes in Chardonnay,Cabernet Sauvignon,Riesling,Merlot,Cabernet Franc,Petit Manseng,Marselen and Tannat,respectively.The results showed that the types and the numbers of the strains in the fermentation of different varieties were different even in the same region in the same year.3.The total of 407 S.cerevisiae isolates were isolated in the spontaneous fermentation in nine varieties in 2013.90 genotypes of S.cerevisiae were distinguished by interdelta sequence analysis among these strains,the number of the genotypes in the fermentation of Chardonnay,Cabernet Sauvignon,Riesling,Merlot,Cabernet Franc,Petit Manseng,Marselen,Tannat and Petit Verdot is 19,16,4,14,12,13,4,10 and 11,respectively.Em-65,C1-12,Ga-17,Lc-26,Pd-41,Id-75,Ma-20,Tb-50 and Pk-47 is the dominant genotypes in Chardonnay,Cabernet Sauvignon,Riesling,Merlot,Cabernet Franc,Petit Manseng,Marselen,Tannat and Petit Verdot,respectively.4.The cluster analysis showed that the S.cerevisiae strains from the same grape variety had smaller genetic differences than those selected from the different grape variety.Besides,the S.cerevisiae strains isolated in 2012 and 2013 have significant genetic differences.