Biotransformation of Linoleic Acid into Hydroxy Fatty Acids and Carboxylic Acids Using a Linoleate Double Bond Hydratase as Key Enzyme

Abstract

Hydroxy fatty acids are used as starting materials for the production of secondary metabolites and signalling molecules as well as in the manufacture of industrial fine chemicals. However, these compounds are usually difficult to produce from renewable biomass by chemical means. In this study, linoleate double bond hydratases of Lactobacillus acidophilus NBRC 13951 were cloned for the first time. These enzymes were highly specific for the hydration of the C‐9 or the C‐12 double bond of unsaturated fatty acids (e.g., linoleic acid). Thereby, the enzymes allowed the selective production of hydroxy fatty acids such as 13‐hydroxy‐cis‐9‐octadecenoic acid and 10‐hydroxy‐cis‐12‐octadecenoic acid from linoleic acid. In addition, the hydroxy fatty acids were further converted into industrially relevant carboxylic acids (e.g., 12‐hydroxy‐cis‐9‐dodecenoic acid, α,ω‐tridec‐9‐enedioic acid) and lactones (i.e., δ‐decalactone, γ‐dodecelactone) via whole‐cell biocatalysis using an enzyme cascade. This study thus contributes to the preparation of hydroxy fatty acids, unsaturated carboxylic acids, and lactones from renewable unsaturated fatty acids.magnified image

Production of δ-decalactone from linoleic acid via 13-hydroxy-9(Z)-octadecenoic acid intermediate by one-pot reaction using linoleate 13-hydratase and whole Yarrowia lipolytica cells

“…2). d-decalactone production from coriolic acid as a substrate by Cladosporium suaveolens (Cardillo et al 1991) and 13-hydroxy-9(Z)-octadecenoic acid by Waltomyces lipofer Oh et al 2015) was performed at 30°C and pH7; and at 28°C and pH7, respectively. d-decalactone production was assessed over 15 h by varying the concentration of Y. lipolytica cells from 10 to 40 g l -1 at 5 g 13-hydroxy-9(Z)-octadecenoic acid l -1 (Fig.…”

“…For the economical production of natural lactones, microbial conversion has been attempted (An and Oh 2013;Jo et al 2014). d-decalactone has been produced from hydroxy fatty acid such as coriolic acid [13-hydroxy-9,11(Z,E)-octadecadienoic acid] and13-hydroxy-9(Z)-octadecenoic acid by microorganisms (Cardillo et al 1991;Albrecht et al 1992;Oh et al 2015). However, the amount of the produced d-decalactone is very low and these hydroxy fatty acids are not cheap.…”

Baeyer-Villiger oxidations: biotechnological approach

“…Carvolactones, interesting building blocks for syntheses of bioactive or natural products, can also serve as monomers for polymer production as they can be subjected to ring-opening polymerization and their olefinic side chains can be easily functionalized and crosslinked. This study demonstrates the potential of artificial enzyme cascades and future industrial applications (Oberleitner et al, 2016).…”

Production of 13S-hydroxy-9(Z)-octadecenoic acid from linoleic acid by whole recombinant cells expressing linoleate 13-hydratase from Lactobacillus acidophilus

“…Not only several bacteria (Hudson et al, 1998;Kishimoto et al, 2003;Takeuchi et al, 2013), but also recombinant E. coli cells expressing linoleate 13-hydratase (Oh et al, 2015) have produced 13-HOD. However, 13-HOD production by wildtype bacteria showed too low productivity and recombinant cells produced 2.24 g l −1 13-HOD for 5 h with a low productivity.…”

“…However, the concentration, productivity, and conversion yield for 13-HOD production by these strains were too low for industrial applications. Recently, genetic information of linoleate 13-hydratase involved in the conversion of linoleic acid to 13-hydroxy-9(Z)-octadecenoic acid (13-HOD) was revealed and characterized (Oh et al, 2015). However, the concentration and productivity of 13-HOD by recombinant whole cells expressing linoleate 13-hydratase was low because the expression of linoleate 13-hydratase and the production of 13-HOD were not optimized.…”