Quantitative metaproteomics reveals composition and metabolism characteristics of microbial communities in Chinese liquor fermentation starters

, the Chinese liquor fermentation starter, contains complex microbial communities that are important for the yield, quality, and unique flavor of produced liquor. However, the composition and metabolism of microbial communities in the different types of high-temperature (i.e., white, yellow, and black ) have not been well understood. Herein, we used quantitative metaproteomics based on data-independent acquisition (DIA) mass spectrometry to analyze a total of 90 samples of white, yellow, and black collected in spring, summer, and autumn, revealing the taxonomic and metabolic profiles of different types of across seasons. Taxonomic composition differences were explored across types of and seasons, where the under-fermented white showed the higher microbial diversity and seasonal stability. It was demonstrated that yellow had higher abundance of saccharifying enzymes for raw material degradation. In addition, considerable seasonal variation of microbial protein abundance was discovered in the over-fermented black , suggesting elevated carbohydrate and amino acid metabolism in autumn black . We expect that this study will facilitate the understanding of the key microbes and their metabolism in the traditional fermentation process of Chinese liquor production.