Profiling of Fungal Diversity and Fermentative Yeasts in Traditional Chinese Xiaoqu.

Chunxiao Wang,Jiadai Tang,Shuyi Qiu

doi:10.3389/fmicb.2020.02103

Abstract

To increase the safety and quality of baijiu and rice wine in China, controlling the use of traditional Xiaoqu by studying the beneficial yeasts present has recently been considered. The fungal diversity of six Chinese Xiaoqu including five traditional and one commercial samples was investigated to screen fermentative yeasts with low yields of higher alcohols. A high throughput sequencing approach detected fifteen fungal species with relative abundance higher than 1%, and displayed dissimilarities of fungal diversity among Xiaoqu samples. The 15 fungal species were composed of 11 filamentous fungi with Rhizopus arrhizus as the most common specie and four yeast species, containing Hyphopichia burtonii, Saccharomyces cerevisiae, Saccharomycopsis fibuligera, and Saccharomycopsis malanga. Classic culture-dependent approaches, including 5.8S-ITS-RFLP analysis and D1/D2 sequencing of the 26S rRNA gene, identified nine yeast species in the five traditional Chinese Xiaoqu. In addition to the four yeast species also detected by high throughput sequencing approach, the other five yeast species isolated were Clavispora lusitaniae, Cryptococcus neoformans, Komagataella pastoris, Trichosporon asahii, and Wickerhamomyces anomalus. Further micro-fermentations of rice wine were performed using 19 single yeast isolates, and after the fermentation of rice wine, higher alcohols and ethanol were analyzed by gas chromatography. Two yeast strains, Saccharomyces cerevisiae FBKL2.8022 and Wickerhamomyces anomalus FBKL2.8023, were found to have low yields of higher alcohols and could produce 11.70%vol and 7.10%vol ethanol separately. 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.

Highlights

Xiaoqu is a traditional fermentation starter in China that utilizes rice as a raw material (Gou et al, 2015; Liu and Sun, 2018)
15 fungal species were detected with relative abundances greater than 1%; Aspergillus cibarius, Aspergillus penicillioides, Hyphopichia burtonii, Monascus purpureus, Mucor indicus, Penicillium citrinum, Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, S. cerevisiae, S’copsis fibuligera, Saccharomycopsis
Increasing attention is being given to maintaining a high standardized quality of baijiu and other traditional Chinese alcoholic beverages such as rice wine, which requires a standardized and well-controlled production process

Summary

Introduction

Xiaoqu is a traditional fermentation starter in China that utilizes rice as a raw material (Gou et al, 2015; Liu and Sun, 2018). Xiaoqu is widely used in South China to produce rice, herbal, chi aroma baijiu and rice wine (Liu and Sun, 2018; Chen et al, 2019). A southwestern province, is Fungal Diversity in Chinese Xiaoqu famous for sauce aroma baijiu as well as traditional rice wine and Xiaoqu. Xiaoqu as a fermentation starter, impacts the flavor and quality of baijiu and rice wine (Jin et al, 2017; Zhang et al, 2018; Chen et al, 2019).

Objectives

Methods

Results

Conclusion