Design of a Self-Sufficient Whole-Cell Cascade for the Production of (R)-Citronellal from Geraniol

作者：Guoxiang Ma, Xiangyu Zhu, Dongxin Zhang, Haoran Li, Jinping Lin, Dongzhi Wei · 发表于：Journal of Agricultural and Food Chemistry · 年份：2024 · DOI：10.1021/acs.jafc.4c08175 · 被引用次数：5 · 研究领域：Enzyme Catalysis and Immobilization、Microbial Metabolic Engineering and Bioproduction、Catalysis for Biomass Conversion

( R )-Citronellal is a key chiral precursor of high-value chemicals, such as the best-selling flavor compound (−)-menthol; however, the conventional synthesis suffers from low yield and unsatisfactory enantioselectivity. In this study, we developed a highly atom-efficient hydrogen-borrowing cascade for the synthesis of ( R )-citronellal from geraniol using alcohol dehydrogenase from Escherichia coli K12 (AdhP) and ene-reductase from Saccharomyces cerevisiae YJM1341 (OYE2p). The key rate-limiting enzyme, AdhP, was subjected to structure-guided semirational engineering, and the triple mutant AdhP 260T/284A/268P (M3) was obtained that demonstrated a 1.28-fold improvement in catalytic efficiency ( k cat / K m ) toward geraniol. After optimization of the reaction conditions, the hydrogen-borrowing cascade system achieved the conversion of 23.14 g/L geraniol into ( R )-citronellal at a conversion rate of 98.23% with 96.7% ee. This work represents an alternative approach for the biosynthesis of ( R )-citronellal without sacrificing a cosubstrate or additional enzymes.