Enzyme Cascade Reactions for the Biosynthesis of Long Chain Aliphatic Amines from Renewable Fatty Acids

Abstract

Enzyme cascade reactions for the synthesis of long chain aliphatic amines such as (Z)-12-aminooctadec-9-enoic acid, 10- or 12-aminooctadecanoic acid, and 10-amino-12-hydroxyoctadecanoic acid from renewable fatty acids were investigated. (Z)-12-aminooctadec-9-enoic acid was produced from ricinoleic acid ((Z)-12-hydroxyoctadec-9-enoic acid) via (Z)-12-ketooctadec-9-enoic acid with a conversion of 71% by a two-step in vivo biotransformation involving a long chain secondary alcohol dehydrogenase (SADH) from Micrococcus luteus and a variant of the amine transaminase (ATA) from Vibrio fluvialis. 10-Aminooctadecanoic acid was prepared from oleic acid ((Z)-octadec-9-enoic acid) via 10-hydroxyoctadecanoic acid and 10-ketooctadecanoic acid by an in vivo three-step biocatalysis reaction involving not only the SADH and ATA variants, but also a fatty acid double bond hydratase (OhyA) from Stenotrophomonas maltophilia. 10-Aminooctadecanoic acid was produced at a total rate of 4.4 U/g dry cells with a conversion of 87% by recombinant Escherichia coli expressing the SADH and ATA variants, and OhyA simultaneously. In addition, bulky aliphatic amines could also be produced by the isolated enzymes (i. e., the SADH, the ATA variants, and a nicotinamide adenine dinucleotide (NADH) oxidase from Lactobacillus brevis) with methylbenzyl-amine or benzylamine as amino donor. This study thus contributes to the biosynthesis of long chain aliphatic amines having two large substituents next to the amine functionality.