Enhancing cider vinegar quality through the synergistic Co-fermentation of Lactiplantibacillus plantarum and Acetobacter pasteurianus: A metabolomic and transcriptomic approach

This study investigated the synergistic effects of Lactiplantibacillus plantarum and Acetobacter pasteurianus co-fermentation on the quality and metabolite profiles of cider vinegar using metabolomic and transcriptomic approaches. Four fermentation systems were established for acetic acid fermentation stage all following an identical alcohol fermentation stage conducted by S. cerevisiae . These systems included pure cultures of A. pasteurianus (S-A) and L. plantarum (S-L), a co-fermentation system (S-AL), and a system with addition of lactic acid (S-Alac). Physicochemical parameters, gene expression, and metabolite profiles were comprehensively analyzed via integration of multi-omics analyses. The co-fermentation system significantly enhanced the glycolysis pathway, increased ethanol conversion efficiency, and elevated the polyphenol and flavonoid contents, thereby improving the antioxidant activity. In contrast, in response to the L. plantarum , A. pasteurianus downregulated genes in TCA cycle while upregulating those involved in the conversion of ethanol to acetic acid. Additionally, co-fermentation significantly promoted the biosynthesis of vitamin C and vitamin E. higher level of floral, fruity, and creamy volatile compounds like nerolidol, linalool, and ethyl acetoin in co-fermentation system, enhancing sensory quality of cider vinegar. These findings provide valuable insights into the microbial interactions and metabolic changes in multi-strain fermentation, highlighting its potential for improving cider vinegar quality. • Co-fermentation systems promoted the glycolytic process. • Co-fermentation boosted the antioxidant activity. • Co-fermentation enhanced the synthesis of vitamin C and E. • The carbohydrate metabolism pathways genes in co-fermented L. plantarum were up. • The oxidative phosphorylation pathway genes in co-fermented A. pasteurianus were down.