Abstract: Sourdough starter is a fermentation starter used in the processing of traditional flour food. Most of the previous studies concerning the microbiology of sourdough starter have focused on the isolation and culture of microorganisms. This paper aimed to reveal the characteristics of fungal community structure in traditional sourdough starters by high-throughput sequencing. To analyze the fungal communities in 18 samples collected from different provinces in China, internal transcribed spacer 1 (ITS1) regions were amplified with by PCR based on metagenomics and high-throughput sequenced with Illumina Miseq. Bioinformatics analysis was carried out on Cloud Service Platform. The results showed that a total of 101 operational taxonomic units (OTUs) were found in the 18 samples, which were assigned to 56 species in 38 genera in 25 families in 15 orders in 9 classes in 4 phyla. Saccharomyces cerevisiae was predominant in most samples. S. cerevisiae, Fungi sp. and unclassified_k__Fungi were found abundant in all samples. Kazachstania bulder, Torulaspora delbrueckii, Candida humili, Candida glabrata and Candida sake were also abundant, but they only existed in single samples. Wickerhamomyces anomalus, Alternaria sp. and Aspergillus penicillioides were not only abundant but also highly frequent in most samples. The fungal community structures in these samples were not significantly dissimilar, and no significant difference was observed between the different types and geographical origins.

Key words: high-throughput sequencing, sourdough starters, fungal community