Bacillus that produces TTMP enhances the total ester content in Baijiu through biofortification

TTMP is a key flavor compound in Baijiu and also has potential health benefits. Bacillus are vital producers of TTMP; however, the connection between Bacillus in strong-flavor Daqu and TTMP is restricted. In this study, morphological and molecular biological screening and identification of Bacillus strains in strong-flavor Daqu were carried out, and their TTMP production capabilities were evaluated. Additionally, the influence of the selected strains on Baijiu flavor was assessed through simulated fermentation experiments. The experimental results demonstrated that out of the 18 strains of Bacillus spores screened, 12 could produce TTMP, indicating a diverse population of Bacillus spores capable of generating pyrazine compounds in Daqu. Among these, Bacillus subtilis YR-5 yields the highest TTMP at 761.32 mg/L, followed by Bacillus velzensis YR-3 and Bacillus velzensis YR-12 with yields of 553.25 mg/L and 341.19 mg/L, respectively. Under simulated fermentation conditions, the TTMP content increased significantly from 0.19 mg/mL to 0.63 mg/mL, 0.92 mg/mL, and 0.53 mg/mL after adding YR-3, YR-5, and YR-12 respectively; meanwhile, ester content in fermentation system increased by 69.84%,79.35%, and 64.15% respectively. These findings imply that the functional microorganisms required in the search for Baijiu can be screened and identified in Daqu, and the selected strains can be utilized for biofortification to enhance the content of TTMP in Baijiu and improve the flavor of Baijiu.