Mandelate Racemase and Mandelate Dehydrogenase Coexpressed Recombinant Escherichia coli in the Synthesis of Benzoylformate

Abstract

Benzoylformate is used widely as an organic synthetic intermediate. Mandelate racemase and mandelate dehydrogenase are two enzymes used in producing benzoylformate from racemic mandelate in microbial metabolism. In the present work, the genes encoding mandelate racemase and mandelate dehydrogenase from Pseudomanas aeruginosa strain NUST were cloned and expressed in Escherichia coli to convert racemic mandelate to benzoylformate. The use of whole resting cells of recombinant E. coli allowed the conversion of 65.7 mM solution of racemic mandelate to benzoylformate at a yield of 98.9% in 45 h. The process is a promising alternative for the production of benzoylformate.