AUTHOR=Cai Wenchao , Xue Yu’ang , Wang Yurong , Wang Wenping , Shu Na , Zhao Huijun , Tang Fengxian , Yang Xinquan , Guo Zhuang , Shan Chunhui 

TITLE=The Fungal Communities and Flavor Profiles in Different Types of High-Temperature Daqu as Revealed by High-Throughput Sequencing and Electronic Senses

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.784651

DOI=10.3389/fmicb.2021.784651

ISSN=1664-302X

ABSTRACT=<p>Polymicrobial co-fermentation is among the distinct character of high-temperature Daqu. However, fungal communities in the three types of high-temperature Daqu, namely, white high-temperature Daqu, black high-temperature Daqu, and yellow high-temperature Daqu, are yet to be characterized. In this study, the fungal diversity, taste, and aroma profiles in the three types of high-temperature Daqu were investigated by Illumina MiSeq high-throughput sequencing, electronic tongue, and electronic nose, respectively. Ascomycota and Basidiomycota were detected as the absolute dominant fungal phylum in all types of high-temperature Daqu samples, whereas <italic>Thermomyces</italic>, <italic>Thermoascus</italic>, <italic>Aspergillus</italic>, <italic>Rasamsonia</italic>, <italic>Byssochlamys</italic>, and <italic>Trichomonascus</italic> were identified as the dominant fungal genera. The fungal communities of the three types of high-temperature Daqu differed significantly (<italic>p</italic> &lt; 0.05), and <italic>Thermomyces</italic>, <italic>Thermoascus</italic>, and <italic>Monascus</italic> could serve as the biomarkers in white high-temperature Daqu, black high-temperature Daqu, and yellow high-temperature Daqu, respectively. The three types of high-temperature Daqu had an extremely significant difference (<italic>p</italic> &lt; 0.01) in flavor: white high-temperature Daqu was characterized by sourness, bitterness, astringency, richness, methane, alcohols, ketones, nitrogen oxides, and sulfur organic compounds; black high-temperature Daqu was characterized by aftertaste-A, aftertaste-B, methane-aliph, hydrogen, and aromatic compounds; and yellow high-temperature Daqu was characterized by saltiness, umami, methane, alcohols, ketones, nitrogen oxides, and sulfur organic compounds. The fungal communities in the three types of high-temperature Daqu were significantly correlated with taste but not with aroma, and the aroma of high-temperature Daqu was mainly influenced by the dominant fungal genera including <italic>Trichomonascus</italic>, <italic>Aspergillus</italic>, <italic>Thermoascus</italic>, and <italic>Thermomyces</italic>. The result of the present study enriched and refined our knowledge of high-temperature Daqu, which had positive implications for the development of traditional brewing technique.</p>