Composite beads of silica gel, alginate and poly(aspartic acid) for the immobilization of a lipase enzyme

Abstract

Silica gel/alginate/poly(aspartic acid) composite beads were prepared for immobilization of lipase B enzyme from Candida antarctica (CaLB). CaLB was first adsorbed on functionalized mesoporous silica gel particles, which were then entrapped in the interpenetrating network of thiolated poly(aspartic acid) and alginate, cross-linked by zinc ions. Finally, the beads were chemically stabilized by poly(ethylene glycol) diglycidyl ether, a bisepoxide cross-linker. In this manner, spherical biocatalysts with a diameter of 3-4 mm were prepared and their biocatalytic performance was tested by kinetic resolution of racemic 1-phenylethanol. The activity of CaLB in the beads was comparable to that of CaLB physically adsorbed on silica gel particles. The composite beads were easy to recover after use and no loss of biocatalytic activity was observed even after five test reaction cycles. Furthermore, the CaLB in the composite beads showed sufficient thermal stability up to 90°C, contrary to CaLB adsorbed only on silica gel particles.

The rise of continuous flow biocatalysis – fundamentals, very recent developments and future perspectives

“…PDE consists of a long and flexible chain attaching the enzyme via multipoint bindings together with an optimal enzyme orientation allowing the best entrance of the substrate into the active site. 112,149,154 4.3.2 Ionic-liquid-modified carriers. The use of bisepoxides presented in the previous paragraph is not the only innovative immobilization method that is based on the use of well-known carrier materials that have already been tested and optimized by chemical modification.…”

Effect of Side Groups on the Hydrolytic Stability of Thiolated and Disulfide Cross-linked Polyaspartamides

“…Synthesis of polysuccinimide: Polysuccinimide was synthesized by the thermal polycondensation of aspartic acid as reported earlier [27]. The viscosity average molecular weight of the polymer was found to be 33 kDa (determined by an Anton Paar Lovis 2000 rolling ball viscometer, Mark−Houwink constants were taken from the literature [28]: K = 1.32 × 10 -1 g/cm 3 and α = 0.76).…”

Immobilization of Phenylalanine Ammonia-lyase via EDTA Based Metal Chelate Complexes – Optimization and Prospects

“…Enzyme immobilization can enhance resistance against the conditions of use (pH, temperature, organic solvents) and give an opportunity for reuse and application in continuous flow mode [4][5][6][7][8][9]. Nowadays there are several well-known methods for enzyme immobilization: covalent immobilization [6,7,[10][11][12][13][14], adsorption [15,16], embedding in polymer [17][18][19] or silica-based matrices [20,21]. New methods have emerged as well over the last decades, in which specifically tagged enzymes can be immobilized via specific interactions [22][23][24][25].…”