Novel oleate hydratases and potential biotechnological applications

Abstract

Oleate hydratase catalyses the addition of water to the CC double bond of oleic acid to produce (R)-10-hydroxystearic acid. The enzyme requires an FAD cofactor that functions to optimise the active site structure. A wide range of unsaturated fatty acids can be hydrated at the C10 and in some cases the C13 position. The substrate scope can be expanded using ‘decoy’ small carboxylic acids to convert small chain alkenes to secondary alcohols, albeit at low conversion rates. Systematic protein engineering and directed evolution to widen the substrate scope and increase the conversion rate is possible, supported by new high throughput screening assays that have been developed. Multi-enzyme cascades allow the formation of a wide range of products including keto-fatty acids, secondary alcohols, secondary amines and α,ω-dicarboxylic acids. Key points • Phylogenetically distinct oleate hydratases may exhibit mechanistic differences. • Protein engineering to improve productivity and substrate scope is possible. • Multi-enzymatic cascades greatly widen the product portfolio.

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…”

“…In general, a number of applications can be envisaged for 10-HSA in the transition from petroleum sources to renewable materials. [31][32][33] Despite its potential future industrial use, no environmental studies on this reaction have been published so far. As the first step for the gate-to-gate analysis, the "functional unit" was defined.…”

“…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][29][30][31][32][33][36][37][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.…”

Selective Supercritical CO2 Extraction and Biocatalytic Valorization of Cucurbita pepo L. Industrial Residuals

“…Specifically, members of the fatty acid ethanolamide family, such as arachidonylethanolamide (AEA, also known as anandamide), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA), show a variety of biological activities, e.g., anti-inflammatory, anorexic effects—useful for appetite control in people with obesity—and analgesic effects [ 24 , 25 ]. On the other side, hydroxy fatty acids (HFAs), obtained by hydration of unsaturated fatty acids (UFAs), are important precursors of flavors, biodegradable polymers, lubricants, cosmetic ingredients, and emulsifiers [ 26 , 27 , 28 , 29 ]. Both enzymatic reactions were first optimized by selection of the respective biocatalyst and biotransformation conditions using standard fatty acids as substrates, then applied to the fatty acid-enriched Cp extracts.…”