Co-expression of alcohol dehydrogenase and aldehyde dehydrogenase in Bacillus subtilis for alcohol detoxification

Alcoholic liver disease is a major cause of morbidity and mortality worldwide. In this work, a food-grade recombinant Bacillus subtilis co-expressing both alcohol dehydrogenase from Saccharomyces cerevisiae (scADH) and aldehyde dehydrogenase from Issatchenkia terricola (istALDH) were successfully constructed via double-crossover homologous recombination. When cultured at 37 °C for 48 h, the activities of scADH and istALDH were 57.56 ± 7.44 and 81.41 ± 8.26 U/mL, respectively. In pH 4.0, the alcohol degradation rate of recombinant B. subtilis fmb8 was 33% and the ΔLog₁₀ was 0.1, indicating that fmb8 could be used as whole-cell biocatalysts for biodegradation of alcohols under low pH conditions. Mice experiments indicated that recombinant B. subtilis significantly alleviate recombinant alcohol-induced increases of mouse liver index, blood alcohol content, and serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities. Furthermore, recombinant B. subtilis significantly reduced liver malondialdehyde levels and increased total antioxidant capacity and superoxide dismutase levels in mouse liver. Overall, our findings suggested that food-grade B. subtilis fmb8 co-expressing scADH and istALDH could be used as a potential probiotic for alcohol detoxification and alleviation of alcoholic liver injury.