AUTHOR=Wang Chunxiao , Tang Jiadai , Qiu Shuyi 

TITLE=Profiling of Fungal Diversity and Fermentative Yeasts in Traditional Chinese Xiaoqu

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.02103

DOI=10.3389/fmicb.2020.02103

ISSN=1664-302X

ABSTRACT=To increase the safety and quality of baijiu and rice wine in China, controlling the use of traditional Xiaoqu by studying the functional yeasts present has recently been considered. The fungal diversity of six Chinese Xiaoqu including five traditional and one commercial samples was investigated to screen functional yeasts with low yields of higher alcohols. A high throughput sequencing approach detected eight primary fungal species (relative abundance higher than 10%), including Aspergillus cibarius, Monascus purpureus, Mucor indicus, Rhizopus arrhizus, Rhizopus microsporus, Saccharomycopsis fibuligera, Wallemia muriae, and Xeromyces bisporus, and displayed dissimilarities of fungal diversity among Xiaoqu samples. Only three yeast species were directly detected from Xiaoqu samples by high throughput sequencing analysis, containing S. fibuligera, Saccharomycopsis malanga, and Saccharomyces cerevisiae, whereas more yeasts were found after enriching by isolation medium. Nine yeast species were isolated and identified in the five traditional Chinese Xiaoqu through classic culture-dependent approaches, including 5.8S-ITS-RFLP analysis and D1/D2 sequencing of the 26S rRNA gene. Further micro-fermentations of rice wine were performed using single yeast isolates, and after the fermentation of rice wine, higher alcohols and ethanol were analyzed by gas chromatography. Two functional yeast strains, Saccharomyces cerevisiae FBKL2.8022 and Wickerhamomyces anomalus FBKL2.8023, were found to have low yields of higher alcohols and could produce a certain amount of ethanol. This study for the first time, to the best of our knowledge, explored the fungal resources in traditional Xiaoqu from different regions of Guizhou, China. The screened S. cerevisiae and W. anomalus strains could be used to establish specific starters to promote the standardization of the production of baijiu and rice wine.