Analysis of fungal community diversity during the fermentation process of Musalesi and screening and identification of superior Saccharomyces cerevisiae

In this study, the diversity of fungal flora in the fermentation process of Musalesi was analyzed by high-throughput sequencing technology, and yeast was isolated and screened by traditional culture separation method combined with morphological observation. Superior Saccharomyces cerevisiae were screened by physiological and biochemical tests, ethanol production, ester production capacity and acid tolerance analysis, and strains were identified by molecular biology technology. The results showed that the richness, uniformity and diversity of fungal flora increased first and then decreased, and a total of 25 fungi genera were identified during the fermentation process of Musalesi. The main fungal genera were Saccharomyces, Aspergillus, Talaromyces, Aureobasidium, Rhodotorula, Filobasidium, Morchella, Fusarium. The dominant fungi genera (relative abundance>1%) at the early stage of fermentation were Rhodotorula, Morchella, Fusarium and Filobasidium, at the middle stage of fermentation, there were Saccharomyces, Aureobasidium, Coriolopsis, Talaromyces, Penicillium, Aspergillus, and at the later stage of fermentation, there were Saccharomyces, Aspergillus, Talaromyces, Filobasidium, Penicillium. A total of two dominant yeast strains (numbered as J-1 and J-6) were isolated and screened in the fermentation process of Musalesi. They were both identified as S. cerevisiae, and their acid resistance and growth performance were superior to commercial S. cerevisiae SY.