Immobilization of lipase on porous monodisperse chitosan microspheres

Thermodynamics, kinetics and optimization of catalytic behavior of polyacrylamide-entrapped carboxymethyl cellulase (CMCase) for prospective industrial use

In the current study, kinetic and thermodynamic parameters of free and polyacrylamide-immobilized CMCase were analyzed. The maximum immobilization yield of 34 ± 1.7% was achieved at 11% acrylamide. The enthalpy of activation (ΔH) of free and immobilized enzyme was found to be 13.61 and 0.29 kJ mol^-1, respectively. Irreversible inactivation energy of free and immobilized CMCase was 96.43 and 99.01 kJ mol^-1, respectively. Similarly, the enthalpy of deactivation (ΔH_d) values for free and immobilized enzyme were found to be in the range of 93.51-93.76 kJ mol^-1 and 96.08-96.33 kJ mol^-1, respectively. Michaelis-Menten constant (K_m) increased from 1.267 ± 0.06 to 1.5891 ± 0.07 mg ml^-1 and the maximum reaction rate (V_max) value decreased (8319.47 ± 416 to 5643.34 ± 282 U ml^-1 min^-1) after immobilization. Due to wide pH and temperature stability profile with sufficient reusing efficiency up to three successive cycles, the immobilized CMCase might be useful for various industrial processes.

Different strategies for the lipase immobilization on the chitosan based supports and their applications

Immobilized enzymes have received incredible interests in industry, pharmaceuticals, chemistry and biochemistry sectors due to their various advantages such as ease of separation, multiple reusability, non-toxicity, biocompatibility, high activity and resistant to environmental changes. This review in between various immobilized enzymes focuses on lipase as one of the most practical enzyme and chitosan as a preferred biosupport for lipase immobilization and provides a broad range of studies of recent decade. We highlight several aspects of lipase immobilization on the surface of chitosan support containing various types of lipase and immobilization techniques from physical adsorption to covalent bonding and cross-linking with their benefits and drawbacks. The recent advances and future perspectives that can improve the present problems with lipase and chitosan such as high-price of lipase and low mechanical resistance of chitosan are also discussed. According to the literature, optimization of immobilization methods, combination of these methods with other techniques, physical and chemical modifications of chitosan, co-immobilization and protein engineering can be useful as a solution to overcome the mentioned limitations.

Synthesis of Benzyl Acetate Catalyzed by Lipase Immobilized in Nontoxic Chitosan-Polyphosphate Beads

Enzymes serve as biocatalysts for innumerable important reactions, however, their application has limitations, which can in many cases be overcome by using appropriate immobilization strategies. Here, a new support for immobilizing enzymes is proposed. This hybrid organic-inorganic support is composed of chitosan-a natural, nontoxic, biodegradable, and edible biopolymer-and sodium polyphosphate as the inorganic component. Lipase B from Candida antarctica (CALB) was immobilized on microspheres by encapsulation using these polymers. The characterization of the composites (by infrared spectroscopy, thermogravimetric analysis, and confocal Raman microscopy) confirmed the hybrid nature of the support, whose external part consisted of polyphosphate and core was composed of chitosan. The immobilized enzyme had the following advantages: possibility of enzyme reuse, easy biocatalyst recovery, increased resistance to variations in temperature (activity declined from 60 °C and the enzyme was inactivated at 80 °C), and increased catalytic activity in the transesterification reactions. The encapsulated enzymes were utilized as biocatalysts for transesterification reactions to produce the compound responsible for the aroma of jasmine.