A Convenient U-Shape Microreactor for Continuous Flow Biocatalysis with Enzyme-Coated Magnetic Nanoparticles-Lipase-Catalyzed Enantiomer Selective Acylation of 4-(Morpholin-4-yl)butan-2-ol

Abstract

This study implements a convenient microreactor for biocatalysis with enzymes immobilized on magnetic nanoparticles (MNPs). The enzyme immobilized onto MNPs by adsorption or by covalent bonds was lipase B from Candida antarctica (CaLB). The MNPs for adsorption were obtained by covering the magnetite core with a silica shell and later with hexadecyltrimethoxysilane, while for covalent immobilization, the silica-covered MNPs were functionalized by a layer forming from mixtures of hexadecyl- and 3-(2-aminoethylamino)propyldimethoxymethylsilanes in 16:1 molar ratio, which was further activated with neopentyl glycol diglycidyl ether (NGDE). The resulting CaLB-MNPs were tested in a convenient continuous flow system, created by 3D printing to hold six adjustable permanent magnets beneath a polytetrafluoroethylene tube (PTFE) to anchor the MNP biocatalyst inside the tube reactor. The anchored CaLB-MNPs formed reaction chambers in the tube for passing the fluid through and above the MNP biocatalysts, thus increasing the mixing during the fluid flow and resulting in enhanced activity of CaLB on MNPs. The enantiomer selective acylation of 4-(morpholin-4-yl)butan-2-ol (±)-1, being the chiral alcohol constituent of the mucolytic drug Fedrilate, was carried out by CaLB-MNPs in the U-shape reactor. The CaLB-MNPs in the U-shape reactor were compared in batch reactions to the lyophilized CaLB and to the CaLB-MNPs using the same reaction composition, and the same amounts of CaLB showed similar or higher activity in flow mode and superior activity as compared to the lyophilized powder form. The U-shape permanent magnet design represents a general and easy-to-access implementation of MNP-based flow microreactors, being useful for many biotransformations and reducing costly and time-consuming downstream processes.

Lanmodulin-Functionalized Magnetic Nanoparticles as a Highly Selective Biosorbent for Recovery of Rare Earth Elements

“…Subsequently, the mixed REE concentrates can be processed into total rare earth oxides (TREOS) or individually separated to produce single-element concentrate through downstream steps such as liquid–liquid extraction, electrodeposition, precipitation, and calcination. ,, Considering industrial applications, the facile construction of the MNP-LanM biosorbent from cell lysates and high stability in reuse are desirable properties for the development of low-cost biosorption technology for REE separation, yet the protein loading capacity on MNPs can be further improved by optimizing the length, density, and composition of the polymers grafted on the MNPs and the size of the MNP inorganic core. Also, conversion from batch operation to a semicontinuous/continuous process with proper design of tube reactors or magnetic separators will be another strategy for scaling up. The MNP-LanM developed in this study will contribute to achieving sustainable management of REE-containing waste while reducing dependence on environmentally unfriendly and energy-intensive ore mining.…”

Magnetically agitated continuous-flow tube reactors with aspartate ammonia-lyase immobilized on magnetic nanoparticles

“…Comparison to the AAL-MNP reaction in static MNP flow reactors (SFRs). Finally, two versions of the static MNP flow reactor (SFR), resembling a single reaction chamber of the recently described tubular reactor with static MNP reaction chambers, 24 were investigated.…”

“…22,23 Recently, in a simplified tubular U-shaped version of such a static MNP-based bioreactor, kinetic resolution of a heterocyclic secondary alcohol by a lipase-MNP biocatalyst had been performed efficiently. 24 Although the examples in the previous section indicated the usefulness of MNP-based flow reactors for biocatalysis, mixing of MNPs during the fluid flow can create a unique opportunity to further enhance the efficiency of microfluidic biocatalytic systems. 25 Since the patents of Herschler first described the basic principle of magnetic mixing in 1965, 26 various magneticparticle (MP)-based reactors were developed for chemical catalysis.…”

“…22,23 Recently, in a simplified tubular U-shaped version of such a static MNP-based bioreactor, kinetic resolution of a heterocyclic secondary alcohol by a lipase-MNP biocatalyst had been performed efficiently. 24…”

The effects of the chemical modification on immobilized lipase features are affected by the enzyme crowding in the support

“…46,47 Lipases are frequently utilized at both academic and industrial levels, [48][49][50][51] with applications as detergents (as fat cleaning), [52][53][54][55] food and feed industries (modifying oils and fats), [56][57][58][59][60][61] fine chemistry (resolution of racemic mixtures, regio-or enantio-selective acylations, etc. ), [62][63][64][65][66][67] polymer science (production or degradation of polymeric materials), [68][69][70][71] or energy (production of biodiesel). [72][73][74][75][76][77] They have a specific catalytic feature: they can act on interfaces.…”