Abstract:In this study，Illumina MiSeq high-throughput sequencing technique was used to analyze the bacterial diversity in Daqu skin and Daqu heart of Houhuo low-temperature Daqu.PICRUSt was applied to predict the gene functions.α diversity analysis found that both bacterial taxa abundance and diversity of species in Daqu skin were higher than in Daqu heart.At the genus level，Streptomyces，Lactobacillus，Pantoea，Erwinia，and Enterobacter were extremely abundant in Daqu skin（P＜0.001），while Saccharopolyspora and Thermoactinomyces were significantly abundant in Daqu heart（P＜0.05）.Bacillus was extremely abundant in Daqu heart（P＜0.001）.β diversity analysis found that there were significant differences between Daqu skin and Daqu heart samples（P＜0.001）.At the level of operational taxonomic units（OTU），there were a large number of core OTU bacterial taxa in the Daqu skin and Daqu heart，while some unique bacterial taxa existed with less content.After linear discriminative analysis effect size（LEfSe）analysis，the flora that resulted in the difference was mainly the dominant bacterial genera such as Streptomyces and Bacillus.PICRUSt identified that amino acid transport and metabolism，carbohydrate transport and metabolism，and transcription were highly expressed among bacterial taxa in Houhuo low-temperature Daqu，and bacteria in Daqu skin showed extremely high expression of in the cytoskeleton（P＜0.01）.In conclusion，the bacterial community structures in the Daqu skin and Daqu heart were significantly different，and the bacterial taxa in the Houhuo low-temperature Daqu had strong functions of amino acid transport and metabolism，and carbohydrate transport and metabolism，and transcription.