Regulation of lactic acid by similar niche strains and their metabolites in Maotai-flavor liquor brewing
Lactic acid is a significant non-volatile organic acid in traditional Baijiu and accumulates progressively in Maotai-flavor liq-uor fermented grains with each brewing cycle.Elevated lactic acid levels in the fermented grains can impede normal fermentation of the liq-uor.However,effective control measures to reduce lactic acid have not been established.This study utilized metagenomic sequencing to an-alyze the microbial community structure in fermented grains at different stacking and fermentation stages,correlating it with changes in lac-tic acid content.It was hypothesized that the accumulation of lactic acid is related to changes in the lactic acid bacterial community.The study also tested the feasibility of using nisin as a control agent for lactic acid.Results indicated that compared to Group 2,which had rap-id lactic acid accumulation,Group 1 exhibited higher lactic acid bacterial diversity.Simulation of fermentation with varying lactobacillus diversity confirmed that lactic acid content decreased with increased microbial diversity.Co-culturing a low lactic acid-producing Lactoba-cillus f er mentum with high lactic acid-producing Lactobacilli in a Transwell system revealed that Lactobacillus fermentum maintained a growth advantage at inoculation ratios even below 50％.The study demonstrated that 1 mg/mL nisin inhibited Lactobacilli without signifi-cantly affecting brewing functional microbes,and it proved that it could control the lactic acid content by controlling the biomass of lactic acid bacteria without interfering with the normal production of liquor,suggesting its potential as a lactic acid control agent.This research provides new insights and theoretical guidance for controlling lactic acid content in Chinese liquor production.
万方数据
维普
