Temperature-driven microbial assembly and flavor compound dynamics in high-temperature Daqu: Adaptive co-evolution for efficient Tetramethylpyrazine production

High-temperature Daqu, as a key starter, initiates the solid-state fermentation of Maotai-flavored Baijiu and substantially influences its flavor profile. Tetramethylpyrazine (TTMP), a key flavor compound in high-temperature Daqu and Maotai-flavored liquor, exhibits unique pharmacological properties, imparting nutty and roasted aromas. This study is based on temperature driven microbial assembly and flavor compound changes in high-temperature Daqu, combined with modular community construction methods and temperature adaptive co-evolution strategies, effectively increasing the content of TTMP. First, through correlation analysis of flavor components, microbial communities, and physicochemical properties during high-temperature Daqu fermentation, we found that temperature drives microbial assembly and TTMP synthesis (r = 0.68, P < 0.05), and that Bacillus, Lactobacillus, and Saccharomyces are strongly correlated with TTMP synthesis (P < 0.05). Subsequently, these strains were screened, and a modular approach was employed to construct a microbial community for TTMP synthesis. Given the continuous high-temperature conditions during the fermentation process of Daqu, we developed a temperature-tolerant and high-yielding synthetic community through a temperature-adaptive co-evolution strategy. Finally, using the evolved synthetic community for laboratory simulation fermentation, the TTMP yield reached 328.5 mg/kg, which was 1.8-fold higher than the pre-evolutionary community simulation fermentation (178.6 mg/kg). In summary, this study significantly increased the yield of TTMP through the temperature-adaptive co-evolution of synthetic communities, offering new ideas and strategies for the targeted regulation of Daqu flavor compounds.