Bienzymatic reaction for hydroperoxide production in a multiphasic system

In-situ co-immobilization of lipase, lipoxygenase and L-cysteine within a metal-amino acid framework for conversion of soybean oil into higher-value products

We propose a co-immobilized chemo-enzyme cascade system to mitigate random intermediate diffusion from the mixture of individual immobilized catalysts and achieve a one-pot reaction of multi-enzyme and reductant. Catalyzed by lipase and lipoxygenase, unsaturated lipid hydroperoxides (HPOs) were synthesized. 13(S)-hydroperoxy-9Z, 11E-octadecadienoic acid (13-HPODE), one compound of HPOs, was subsequently reduced to 13(S)-hydroxy-9Z, 11E-octadecadienoic acid (13-HODE) by cysteine. Upon the optimized conditions, 75.28 mg of 13-HPODE and 4.01 mg of 13-HODE were produced from per milliliter of oil. The co-immobilized catalysts exhibited improved yield compared to the mixture of individually immobilized catalysts. Moreover, it demonstrated satisfactory durability and recyclability, maintaining a relative HPOs yield of 78.5% after 5 cycles. This work has achieved the co-immobilization of lipase, lipoxygenase and the reductant cysteine for the first time, successfully applying it to the conversion of soybean oil into 13-HODE. It offers a technological platform for transforming various oils into high-value products.

Synthesis of Linoleic Acid 13-Hydroperoxides from Safflower Oil Utilizing Lipoxygenase in a Coupled Enzyme System with In-Situ Oxygen Generation

Linoleic acid hydroperoxides are versatile intermediates for the production of green note aroma compounds and bifunctional ω-oxo-acids. An enzyme cascade consisting of lipoxygenase, lipase and catalase was developed for one-pot synthesis of 13-hydroperoxyoctadecadienoic acid starting from safflower oil. Reaction conditions were optimized for hydroperoxidation using lipoxygenase 1 from Glycine max (LOX-1) in a solvent-free system. The addition of green surfactant Triton CG-110 improved the reaction more than two-fold and yields of >50% were obtained at linoleic acid concentrations up to 100 mM. To combine hydroperoxidation and oil hydrolysis, 12 lipases were screened for safflower oil hydrolysis under the reaction conditions optimized for LOX-1. Lipases from Candida rugosa and Pseudomonas fluorescens were able to hydrolyze safflower oil to >75% within 5 h at a pH of 8.0. In contrast to C. rugosa lipase, the enzyme from P. fluorescens did not exhibit a lag phase. Combination of P. fluorescens lipase and LOX-1 worked well upon LOX-1 dosage and a synergistic effect was observed leading to >80% of hydroperoxides. Catalase from Micrococcus lysodeikticus was used for in-situ oxygen production with continuous H2O2 dosage in the LOX-1/lipase reaction system. Foam generation was significantly reduced in the 3-enzyme cascade in comparison to the aerated reaction system. Safflower oil concentration was increased up to 300 mM linoleic acid equivalent and 13-hydroperoxides could be produced in a yield of 70 g/L and a regioselectivity of 90% within 7 h.

Biocatalytic Synthesis of Natural Green Leaf Volatiles Using the Lipoxygenase Metabolic Pathway

In higher plants, the lipoxygenase enzymatic pathway combined actions of several enzymes to convert lipid substrates into signaling and defense molecules called phytooxylipins including short chain volatile aldehydes, alcohols, and esters, known as green leaf volatiles (GLVs). GLVs are synthesized from C18:2 and C18:3 fatty acids that are oxygenated by lipoxygenase (LOX) to form corresponding hydroperoxides, then the action of hydroperoxide lyase (HPL) produces C6 or C9 aldehydes that can undergo isomerization, dehydrogenation, and esterification. GLVs are commonly used as flavors to confer a fresh green odor of vegetable to perfumes, cosmetics, and food products. Given the increasing demand in these natural flavors, biocatalytic processes using the LOX pathway reactions constitute an interesting application. Vegetable oils, chosen for their lipid profile are converted in natural GLVs with high added value. This review describes the enzymatic reactions of GLVs biosynthesis in the plant, as well as the structural and functional properties of the enzymes involved. The various stages of the biocatalytic production processes are approached from the lipid substrate to the corresponding aldehyde or alcoholic aromas, as well as the biotechnological improvements to enhance the production potential of the enzymatic catalysts.

Selective Production of 9R-Hydroxy-10E,12Z,15Z-Octadecatrienoic Acid from α-Linolenic Acid in Perilla Seed Oil Hydrolyzate by a Lipoxygenase from Nostoc Sp. SAG 25.82

Hydroxy fatty acids (HFAs) derived from omega-3 polyunsaturated fatty acids have been known as versatile bioactive molecules. However, its practical production from omega-3 or omega-3 rich oil has not been well established. In the present study, the stereo-selective enzymatic production of 9R-hydroxy-10E,12Z,15Z-octadecatrienoic acid (9R-HOTE) from α-linolenic acid (ALA) in perilla seed oil (PO) hydrolyzate was achieved using purified recombinant 9R-lipoxygenase (9R-LOX) from Nostoc sp. SAG 25.82. The specific activity of the enzyme followed the order linoleic acid (LA) > ALA > γ-linolenic acid (GLA). A total of 75% fatty acids (ALA and LA) were used as a substrate for 9R-LOX from commercial PO by hydrolysis of Candida rugosa lipase. The optimal reaction conditions for the production of 9R-HOTE from ALA using 9R-LOX were pH 8.5, 15°C, 5% (v/v) acetone, 0.2% (w/v) Tween 80, 40 g/L ALA, and 1 g/L enzyme. Under these conditions, 9R-LOX produced 37.6 g/L 9R-HOTE from 40 g/L ALA for 1 h, with a conversion yield of 94% and a productivity of 37.6 g/L/h; and the enzyme produced 34 g/L 9R-HOTE from 40 g/L ALA in PO hydrolyzate for 1 h, with a conversion yields of 85% and a productivity of 34 g/L/h. The enzyme also converted 9R-hydroxy-10E,12Z-octadecadienoic acid (9R-HODE) from 40 g/L LA for 1.0 h, with a conversion yield of 95% and a productivity of 38.4 g/L. This is the highest productivity of HFA from both ALA and ALA-rich vegetable oil using LOX ever reported. Therefore, our result suggests an efficient method for the production of 9R-HFAs from LA and ALA in vegetable oil using recombinant LOX in biotechnology.

Amperometric biosensor based on Prussian Blue-modified screen-printed electrode for lipase activity and triacylglycerol determination

Lipase activity against triacylglycerols has been measured using an amperometric enzyme biosensor based on glycerol dehydrogenase/NADH oxidase. A Prussian Blue modified screen-printed electrode was selected as substrate for the two immobilised-enzyme systems due to their higher operative stability reported in previous works. Various parameters such as cofactor (flavin mononucleotide FMN) concentration (1 mM), NAD+ coenzyme concentration (2 mM), pH effect (phosphate buffer pH 6 to 8, Tris buffer pH 8-10) response time and storage stability were evaluated and optimised. The glycerol biosensor was then investigated for lipase activity. The system was challenged against an olive or sunflower oil real samples in order to detect fatty acids and the results were compared with those provided either by the manufacture or reference methods with good agreement.

Synthesis of a novel macrolactone by lipase-catalyzed intra-esterification of hydroxy-fatty acid in organic media

The unsaturations and groups bound to the ring and to the lateral chain of lactones give a large diversity in this class of molecules. In this work we produced enzymatically a macrolactone in organic media. The substrate used was a hydroxy-fatty acid: (+)-coriolic acid and the enzymes tested were free or immobilized microbial lipases. The immobilized lipase from Candida antarctica seems to be the most adequate catalyst offering a high reaction yield. The intra-esterification was studied as a function of temperature and type of solvent. Higher yields were obtained when using diisopropyl-ether at 35 degrees C. This reaction, involving an alcohol group on an internal position on the carbon chain of the substrate hydroxy-acid, produces an original lactone: 13S-octadeca-(9Z,11E)-dienolide. The product was purified and characterized using (1)H nuclear magnetic resonance spectroscopy, mass spectrometry and infrared spectroscopy.