Abstract:The staple food of ethnic minorities in Xinjiang，China，is Nang，which consists mainly of traditional sour dough （fermentation head）.The microbial composition in sour dough directly affects the quality and nutritional value of Nang.To clarify the microbial composition of Nang sour dough，12 samples were collected from seven regions（Hami，Korla，Changji，Ili，Aksu，Kashgar，and Alar）in Xinjiang.Fungi（229 strains）were isolated and purified from fermented sour dough in different areas by traditional isolation and culture methods.A total of 7 genera and 9 species were identified.These included 129 strains of Saccharomyces cerevisiae，19 strains of Pichia kluyveri，18 strains of Wickerhames anomalus，17 strains of Kodamaea ohmeri，12 strains of Candida zeylanoides，11 strains of Saccharomycosis fibuligera，10 strains of Pichia kudriavzevii，7 strains of C.parapsilosis，and 6 strains of Rhodotorula mucilaginosa.Furthermore，80 strains of lactic acid bacteria，4 genera and 7 species were identified，including 46 strains of Lactobacillus pentosus，10 strains of L.paracasei，9 strains of L.casei，7 strains of L.paralimentarius，5 strains of Pediococcus pentosaceus，2 strains of Weissella cibaria，and 1 strain of Leuconostoc citreum.There were 17 strains of other bacteria including 11 strains of Acetobacter malorum，3 strains of Staphylococcus epidermidis，and 3 strains of Bacillus siamesis.The dominant microorganisms were S.cerevisiae and L.pentosus，accounting for 56.3% of fungi and 57.5% of bacteria，respectively.