Effect of Cellulase-Producing Bacteria on Fungi Community Structure and Ester Generation in Chinese Liquor Fermenting Grains

ABSTRACT

To study cellulase-producing bacteria's role in the fungi community and ester generation during fermentation of Chinese liquor fermenting grains, a cellulase-producing bacteria strain was added to fermenting grains at different levels. The fungi community structure and diversity in Chinese liquor fermenting grains was studied, using high-throughput sequencing. Results show that fermenting grains’ fungi community structure changed with fermentation time, and the changes were dependent on the type of fermenting grains. This illustrated that addition of cellulase-producing bacteria had impacted the fermenting grains’ fungi community structure. Diversity analysis showed that the addition of cellulase-producing strain had no obvious effect on fungi community's abundance index (Ace/Chao), while there was a significant influence on fungi community's Shannon and Simpson index. Correlation analysis showed that the addition of the cellulase-producing strain had significant positive correlation with the fungi community's Shannon index, and had a significant negative correlation with the fungi community's Simpson index. The conclusion was that the addition of the cellulase-producing strain significantly improved the fungi community's richness, but reduced its dominance, and this increased the fungi community's uniformity in the fermenting grains. As a result of this change, total ester, ethyl acetate, ethyl butyrate, and ethyl caproate content in the fermenting grains and liquor significantly increased, while the ethyl lactate content decreased when 10⁶ cfu/g of cellulase-producing bacteria were added.

KEYWORDS:

• Chinese liquor
• diversity
• ferment
• fermenting grains
• fungi community structure
• high-throughput sequencing

Additional information

Funding

This work was supported by the Natural fund of the Heilongjiang province (surface project, grant number: C2017066).