Towards an understanding of oleate hydratases and their application in industrial processes

Abstract

Fatty acid hydratases are unique to microorganisms. Their native function is the oxidation of unsaturated C–C bonds to enable detoxification of environmental toxins. Within this enzyme family, the oleate hydratases (Ohys), which catalyze the hydroxylation of oleic acid to 10-(R)-hydroxy stearic acid (10-HSA) have recently gained particular industrial interest. 10-HSA is considered to be a replacement for 12-(R)-hydroxy stearic acid (12-HSA), which has a broad application in the chemical and pharmaceutical industry. As 12-HSA is obtained through an energy consuming synthesis process, the biotechnological route for sustainable 10-HSA production is of significant industrial interest. All Ohys identified to date have a non-redox active FAD bound in their active site. Ohys can be divided in several subfamilies, that differ in their oligomerization state and the decoration with amino acids in their active sites. The latter observation indicates a different reaction mechanism across those subfamilies. Despite intensive biotechnological, biochemical and structural investigations, surprising little is known about substrate binding and the reaction mechanism of this enzyme family. This review, summarizes our current understanding of Ohys with a focus on sustainable biotransformation.

On the need for gate-to-gate environmental metrics in biocatalysis: fatty acid hydration catalyzed by oleate hydratases as a case study

“…28–30 Several updated comprehensive reviews discuss the topic in detail. 31–33 10-Hydroxystearic acid (10-HSA) has found industrial applications as a natural emollient, a surfactant, and a thickener in the cosmetic industry. Given its functionalization, 10-HSA has been assessed in the polymer industry as well.…”

“…In general, a number of applications can be envisaged for 10-HSA in the transition from petroleum sources to renewable materials. 31–33…”

“…A water–glycerol–ethanol mixture was set as the reaction medium, 36 and loadings of oleic acid in the range of 25–200 g L −1 were assumed, according to most of the prominent examples reported in the literature when industrial applications are envisioned. 28–33,36–38,45 Whole-cell biocatalysts overexpressing OHY were used (range of 50 g cells per L). Two yields were assumed: 75% as a realistic achievement or 100% as the best-case scenario.…”

Mastering targeted genome engineering of GC-rich oleaginous yeast for tailored plant oil alternatives for the food and chemical sector

“…Accordingly, the absence of the two PUFAs (C18:2 and C18:3) in ∆D12 resulted in higher oxidative stability of the oil (Additional File 2 : Table S1). Furthermore, C18:1 can be channelled into the production of other valuable compounds such as 10-(R)-hydroxy stearic acid [ 38 , 39 ] by expressing additional enzymes in the respective strains.…”

Expanding the Portfolio by a Novel Monomeric Oleate Hydratase from Pediococcus parvulus

“…Oleate hydratases belong to the class of fatty acid hydratases (EC 4.2.1.53) and have great potential to become a useful industrial biocatalyst for the generation of valuable fatty acid derivates such as ( R )‐10‐hydroxy stearic acid (10‐HSA), which is considered as a replacement for ( R )‐12‐hydroxy stearic acid (12‐HSA), an industrial product applied as lubricant and emollient. 12‐HSA is currently generated by chemical hydrogenation of castor oil under extreme pressure and temperature with the help of metal catalysts, thus calling for a more eco‐friendly alternative process [5] . Furthermore, hydroxylated fatty acids are valuable precursors for flavor lactones, where some fatty acid based lactones convey fruity and milky odors [15] .…”