Two-step biocatalytic reaction using recombinant Escherichia coli cells for efficient production of phenyllactic acid from l-phenylalanine

摘要

3-Phenyllactic acid (PLA) is a natural product with broad and effective antimicrobial activity that is often used as a preservative in the food industry and as feed additive to replace antibiotics in livestock feeds. In this study, a two-step biocatalytic process for production of PLA from 1-phenylalanine was developed and investigated. In the first step, 1-phenylalanine was converted to phenylpyruvic acid (PPA) by recombinant Escherichia coil cells expressing membrane-bound 1-amino acid deaminase from Proteus vulgaris. In the second step, unpurified PPA was directly converted to PLA by recombinant E. coil cells co-expressing d-2-hydroxyisocaproate dehydrogenase from Lactobacillus delbrueckii subsp. buigaricus and formate dehydrogenase from Mycobacterium vaccae N10. Through two-step cascade reactions, 121 mM PLA was produced from 150 mM 1-phenylalanine with a yield of 81.3%. Thus, this process showed great production efficiency and is a promising method for industrial production of PLA.