本文采用宏基因组学技术对酱香型白酒第四轮次窖内酒醅的优势菌区系变化、代谢功能差异及其相关性进行分析研究。结果表明，窖内酒醅处于酸性环境，发酵30 d风味与发酵0 d相比醇、酸类含量增加，酯类种类丰富；菌群多样性呈降低趋势，共发现细菌属409个，真菌属40个；发酵30 d时优势细菌为乳球菌属（33.83%）、肠球菌属（32.4%）、芽孢杆菌属（14.07%）和分枝杆菌属（8.62%）等，优势真菌为裂殖酵母属（22.26%）、曲霉属（19.58%）、丝衣霉属（14.64%）和毕赤酵母属（13.78%）等。KEGG分析表明碳水化合物代谢和氨基酸代谢为窖内发酵的主要代谢功能，其中曲霉属、莫氏黑粉菌属和毕赤酵母属与两种主要代谢功能具有强的正相关性，而乳球菌属、芽孢杆菌属和分枝杆菌属与其呈现较强负相关。研究结果为解析优势发酵菌及其代谢功能对酱香风味形成提供重要参考。

In this work, metagenomics technology was used to study and analyze the dominant bacteria and fungi communities change, metabolic function difference and correlation of fermented grains in the fourth round of Maotai-flavor liquor cellar. The results showed that the pit fermentation grains were in acid environment, the content of alcohol and acid in 30 days fermentation were higher than that of 0 days fermentation, and the types of esters were more abundant. The diversity decreased after 30 days fermentation, and a total of 409 bacteria genera and 40 fungi genera were found in pit fermentation grains. The dominant bacteria at 30 days fermentation were Lactococcus (21.3%), Enterococcus (21.71%), Bacillus (10.92%) and Mycolicibacterium(8.26%), etc. The dominant fungi were Schizosaccharomyces (22.26%), Aspergillus (19.58%), Byssochlamys(14.64%) and Pichia (13.78%). The KEGG analysis showed that carbohydrate metabolism and amino acid metabolism were the main metabolic functions of microorganism during pit fermentation. Aspergillus, Moesziomyces, Pichiahadstrong positive correlations with the two major metabolic functions, while the Lactococcus, Bacillus and Mycolicibacterium were negatively correlated with them. Theseresults could provide an important reference for the analysis of dominant fermentation microorganisms and their metabolic functions in the formation of Maotai-flavor.

国家自然科学基金项目（31460444）