Project description:Fermented foods are microbial ecosystems in which bacteria and fungi convert raw ingredients into stable, nutritious, and health-promoting products. The composition and activity of these microorganisms determine the biochemical and nutritional profile of the final food. We analyzed 17 fermented foods, each in triplicate, using metaproteomics. This analysis revealed that microbial proteins contribute up to 11% of total protein and 60% of identified proteins. Detailed information on file-naming conventions (database files, MS raw files, and output files), as well as food source suppliers, fermenting microorganisms, peptide loading volumes, and LC-MS gradient lengths, is provided in the table FileAndSampleDescription_PRIDE_submission.csv.
Project description:Highland barley liquor is a distilled spirit made from highland barley on the Tibetan Plateau, but its alcohol yield is limited by the high fiber content of the raw material. In the field of biomass resources, functional microorganisms are commonly used in pretreatment to degrade cellulose and other substances, improving fermentation output. In this study, we isolated the cellulose-degrading probiotic Lactobacillus delbrueckii GR-8 (CMCase 6.21 U/mL) from the traditional vegetable-based fermented food "Jiangshui" and applied biological pretreatment to the fermentation of highland barley liquor. During pretreatment, probiotics enhanced cellulase and amylase activities in the fermented grains, resulting in a 25% reduction in cellulose content and a 112% increase in free reducing sugar content. The pretreatment significantly altered the microbial community structure, enhancing microbial diversity. After distillation, alcohol yield increased by 3.5%, and total acid and ester contents rose by 25% and 23%, respectively. Pyrazine compounds increased by 1290%, while higher alcohols like nonanol, phenylethanol, and hexanol decreased. The treated liquor caused less harm to mice, who showed improved memory, motor skills, and lower oxidative liver damage. This study demonstrates that biological pretreatment enhances both fermentation and the quality of Chinese spirits.
