Ferulic acid production by metabolically engineered Escherichia coli

Abstract Ferulic acid ( p -hydroxy-3-methoxycinnamic acid, FA) is a natural active substance present in plant cell walls, with antioxidant, anticancer, antithrombotic and other properties; it widely used medicine, food, cosmetics. Production of FA by eco?friendly bioprocess great potential. In this study, was biosynthesized metabolically engineered Escherichia coli . As the first step, genes tal (encoding tyrosine ammonia-lyase, Rs TAL) from Rhodobacter sphaeroides , sam5 p- coumarate 3-hydroxylase, Se SAM5) Saccharothrix espanaensis comt Caffeic O -methytransferase, Ta CM) Triticum aestivum were cloned an operon on pET plasmid backbone, E. strain containing construction proved to produce L -tyrosine successfully, confirmed function CM as caffeic -methytransferase. Fermentation result revealed JM109(DE3) more suitable host for production than BL21(DE3). After that expression strength pathway optimized tuning promoter (T7 or T5 promoter) copy number (pBR322 p15A), combination p15a-T5 works best. To further improve production, native pntAB encoding pyridine nucleotide transhydrogenase, selected five NADPH regeneration supplement redox cofactor converting -coumaric into biosynthesis process. Sequentially, convert FA, non-native methionine kinase (MetK Streptomyces spectabilis ) also overexpressed. Based flask fermentation data which show produced 212 mg/L 11.8 residue, could be concluded highest yield achieved K-12 strains reported best our knowledge.