Analysis of fungal flora diversity in low-temperature Daqu with different fermentation stages

Abstract

The diversity of fungal flora and the succession law of fungal flora structure in different fermentation stages of low-temperature Daqu were analyzed and explored by IlluminaMiSeq high-throughput sequencing technology. The results showed that from the time before storage to the time when Daqu was dismantled, the Chao 1 and Shannon indexes of fungal flora in low-temperature Daqu increased from 156 and 2.90 to 376 and 4.29, respectively, and they all increased significantly in the stages of Shangmei, Qichaohuo and Chaohuo (P<0.05). The results of Mahalanobis distance cluster analysis showed that the community structure of low-temperature Daqu fungi in each stage was different before the Chaohuo stage, but it tended to be stable after the Chaohuo stage. During the fermentation of low-temperature Daqu, 9 kinds of dominant fungi genera (average relative abundance>1.0%) were noted, including Saccharomycosis, Wickerhamomyces, Aspergillus, etc. Before storage, Wickerhamomyces and Saccharomycosis were the main fungi. Saccharomycopsis and Rhizopus were the main fungi after Shangmei stage. During the whole fermentation process, the core groups were Wickerhamomyces, Saccharomyces and Hanseniaspora, etc., while the unique groups after storage were mainly composed of Rhizopus and Saccharomyces, etc. It could be seen that Shangmei, Qichaohuo and Chaohuo stages could promote the richness and diversity of fungi in low-temperature Daqu, and the Chaohuo stage had a positive impact on the stability of fungal community structure in Daqu.

Keywords

• low-temperature daqu|fermentation process|illumina miseq high-throughput sequencing|fungal|succession