No abstract

Understanding how Baijiu facilitates blood circulation and prevents blood stasis is crucial for revealing the mechanism of Baijiu for cardiovascular disease (CVD) risk reduction. Here we established a zebrafish thrombosis model induced using arachidonic acid (AA) to quantitatively evaluate the antithrombotic effect of Wuliangye Baijiu. The prevention and reduction effects of aspirin, Wuliangye, and ethanol on thrombosis were compared using imaging and molecular characterization. Wuliangye Baijiu reduces thrombotic risks and oxidative stress in the AA-treated zebrafish, while ethanol with the same concentration has no similar effect. The prevention and reduction effects of Wuliangye on thrombosis are attributed to the change in the metabolic and signaling pathways related to platelet aggregation and adhesion, oxidative stress and inflammatory response.

Catabolic acetolactate synthase (cALS) plays a crucial role in the quality of liquor because of its ability to catalyze the synthesis of the endogenous precursor product α-acetolactate of the aromatic compound tetramethylpyrazine (TTMP) and acetoin. However, the vulnerability of cALS to acidic conditions limits its application in the Chinese liquor brewing industry. Here we report the biochemical characterization of cALS from B. licheniformis T2 (BlALS) that was screened from Chinese liquor brewing microorganisms. BlALS showed optimal activity levels at pH 7.0, and the values of K m and V max were 27.26 mM and 6.9 mM•min −1 , respectively. Through site-directed mutagenesis, we improved the stability of BlALS under acidic conditions. Replacing the two basic residues of BlALS with acidic mutations (N210D and H399D) significantly improved the acid tolerance of the enzyme with a prolonged half-life of 2.2 h (compared with wild-type BlALS of 0.8 h) at pH 4.0. Based on the analysis of homologous modeling, the positive charge area of the electrostatic potential on the protein surface and the number of hydrogen bonds near the active site increased, which helped BlALS N210D−H399D to withstand the acidic environment; this could extend its application in the food fermentation industry.