Interaction-driven chorismate metabolic reprogramming underlies Bacillus–Pediococcus synergistic thermogenesis in high-temperature Daqu

Abstract

High-temperature Daqu (HTD), the essential solid-state fermentation starter for premium Moutai-flavor Baijiu, reaches a peak temperature of 60–65 °C driven by microbial metabolic heat; yet the detailed metabolic mechanism underlying the Bacillus–Pediococcus thermogenic synergy remains largely unresolved. This study integrated isothermal microcalorimetry, time-resolved transcriptomics, and untargeted metabolomics to decipher this cooperative thermogenesis under heat stress, with further validation in a simulated HTD-making system. A network of metabolic interaction and flux redirection was identified, in which heat-induced cell turnover releases cellular nitrogen into a shared pool, and Pediococcus contributes aromatic amino acid biosynthesis that supports respiratory heat output in Bacillus. Chorismate was identified as a central metabolic branch point, where flux is redirected toward tyrosine and menaquinone biosynthesis to sustain metabolic turnover, enhance electron transport efficiency, and alleviate oxidative damage. These findings provide a theoretical basis for precise and standardized industrial production of HTD.