Abstract: In this study, yeasts were isolated and purified from the traditional fermentation starter (Daqu) for Laobaigan liquor. The isolates were identified by morphology as well as polymerase chain reaction-restriction fragment length polymorphism?(PCR-RFLP) analysis of ribosomal 26S rDNA. Meanwhile, yeasts were identified by culture-independent method, namely polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Total DNA was extracted from Daqu and amplified by PCR. The PCR products?were fingerprinted by denaturing gradient gel electrophoresis (DGGE) and were excised and recovered from the gel. The results showed that a total of 57 strains of yeast assigned to 6 kinds of morphology were isolated by traditional culture method and were identified as Pichia kudriavzevii, Clavispora lusitaniae, Wickerhamomyces anomalus, Rhodotorula mucilaginosa, and Trichosporon asahii. A total of 10 strains of yeast were obtained by PCR-DGGE, including one strain of W. anomalus, one strain of Wickerhamomyces sp., one strain of T. asahii, one strain of Candida tropicalis, one strain of Candida sp. two strains of Hyphopichia burtonii and three strains of uncultured Saccharomycopsis. Ten yeast strains belonging to eight genera were identified by culture-dependent and culture-independent methods, including P. kudriavzevii, C. lusitaniae, W. anomalus, R. mucilaginosa, T. asahii, uncultured Saccharomycopsis, H. burtonii, Wickerhamomyces sp., C. tropicalis, and Candida sp.. The results from this study provide a basis for further study on the fermentation performance of Daqu .

Key words: Laobaigan liquor Daqu, yeast, diversity, 26S rDNA PCR-RFLP, PCR-DGGE