Analysis of Fungal Diversity and Isolation and Identification of Yeast in High-temperature and Medium-high-temperature Daqu Using Three Generation Sequencing Technology

To elucidate the variations in fungal diversity and cultivable yeast in different types of Daqu, third-generation sequencing technology was employed to analyze the fungal communities in high-temperature and medium-high-temperature Daqu. Additionally, traditional microbial pure culture methods and molecular biology techniques were utilized to investigate the yeast resources within Daqu. Alpha diversity analysis revealed significant differences (P<0.05) in the richness and diversity of fungal communities between the two types of Daqu. The sequencing data indicated that Thermomyces lanuginosus predominated in high-temperature Daqu, with an average relative content of 73.81%, while medium-high-temperature Daqu was primarily composed of Aspergillus proliferans, representing an average relative content of 52.58%. Beta diversity analysis demonstrated a notable distinction in the fungal community structure between high-temperature and medium-high-temperature Daqu (P<0.01). Moreover, the LEfSe analysis identified Thermomyces and Aspergillaceae as potential biomarkers for high-temperature and medium-high-temperature Daqu, respectively. Pure culture results revealed 18 yeast strains isolated from 10 Daqu samples, with Saccharomycopsis fibuligera identified as the dominant yeast strain in both high-temperature and medium-high-temperature Daqu. These findings underscore pronounced differences in fungal diversity between high-temperature and medium-high-temperature Daqu.