Highly Productive Oxidative Biocatalysis in Continuous Flow by Enhancing the Aqueous Equilibrium Solubility of Oxygen

Abstract

We report a simple, mild, and synthetically clean approach to accelerate the rate of enzymatic oxidation reactions by a factor of up to 100 when compared to conventional batch gas/liquid systems. Biocatalytic decomposition of H O is used to produce a soluble source of O directly in reaction media, thereby enabling the concentration of aqueous O to be increased beyond equilibrium solubility under safe and practical conditions. To best exploit this method, a novel flow reactor was developed to maximize productivity (g product L h ). This scalable benchtop method provides a distinct advantage over conventional bio-oxidation in that no pressurized gas or specialist equipment is employed. The method is general across different oxidase enzymes and compatible with a variety of functional groups. These results culminate in record space-time yields for bio-oxidation.

A Retro‐biosynthesis‐Based Route to Generate Pinene‐Derived Polyesters

“…Aligned with this finding, it has recently been shown that the CHMO from A. calcoaceticus can process bulky α,α‐dialkyl cyclic ketones . Further reaction optimization for enhanced oxygen supply, in combination with protein engineering, could increase the enzymatic transformation to reach industrially relevant conversion and amounts of the lactone. To the best of our knowledge, bicyclic α‐pinene‐derived lactone 10 has not yet been explored and is currently unknown in terpene metabolic pathways .…”

“…To determine if the different activities shown on 2 of the variants could lead to higher activity on the bulkier substrate 9 , the variants were tested for the biocatalytic conversion of 9 into 10 . Whereas CHMO Acineto _QM showed no conversion (Table ) under our screening conditions (in a deep‐well plate under suboptimal oxygen supply conditions; see the Experimental Section), several variants that readily oxidized 9 into 10 were identified. Specifically, the variant L426A showed a conversion of 5 % of 9 into 10 , which was the highest among all 26 variants.…”

Continuous Biocatalysis in Environmentally‐Friendly Media: A Triple Synergy for Future Sustainable Processes

“…In a different area, oxidations are industrially relevant reactions which often use hazardous chemocatalysts and solvents, under environmentally‐unfriendly operational conditions . Herein, biocatalysis may become an interesting alternative.…”

Catalytic Aerobic Oxidation of C(sp3)−H Bonds

“…[144] To avoid superstoichiometric addition of NADPH cofactor in this oxidation reaction, heterologous coexpression of aglucose dehydrogenase (GDH) was used to allow cofactor regeneration with glucose.T his process was limited by O 2 mass transfer and self-deactivation of the catalyst. [146] An example of directed engineering was reported by Li et al where terminal-selective (w)c ytochrome P450pyr was engineered for the subterminal (w-1) hydroxylation of octane with excellent regio-and enantioselectivity in six mutation cycles (Scheme 30). Bühler et al presented an elegant solution to the problem of O 2 mass transfer limitation.…”