Immobilization of Candida antarctica lipase B by covalent attachment to green coconut fiber

Abstract

The objective of this study was to covalently immobilize Candida antarctica type B lipase (CALB) onto silanized green coconut fibers. Variables known to control the number of bonds between enzyme and support were evaluated including contact time, pH, and final reduction with sodium borohydride. Optimal conditions for lipase immobilization were found to be 2 h incubation at both pH 7.0 and 10.0. Thermal stability studies at 60 degrees C showed that the immobilized lipase prepared at pH 10.0 (CALB-10) was 363-fold more stable than the soluble enzyme and 5.4-fold more stable than the biocatalyst prepared at pH 7.0 (CALB-7). CALB-7 was found to have higher specific activity and better stability when stored at 5 degrees C. When sodium borohydride was used as reducing agent on CALB-10 there were no improvement in storage stability and at 60 degrees C stability was reduced for both CALB-7 and CALB-10.

Immobilization of Low-Cost Alternative Vegetable Peroxidase (Raphanus sativus L. peroxidase): Choice of Support/Technique and Characterization

“…The literature reports the immobilization of commercial peroxidase (HRP) by covalent binding (CB) and physical adsorption (PA) in a lignocellulosic material-sugarcane bagasse-as organic support [35]. In the same way, other enzymes were immobilized on coconut fiber [36][37][38][39], an important bio-residue of world agribusiness [40,41]. Calcium alginate microspheres also were used as organic support for enzyme immobilization due to be material of easy synthesis, inexpensive and non-toxic [42][43][44].…”

Catalyzed Ester Synthesis UsingCandida rugosaLipase Entrapped by Poly(N-isopropylacrylamide-co-itaconic Acid) Hydrogel

“…In the last years, several research groups studied the immobilization of the Candida rugosa lipase enzyme onto hydrogels [13–21]. The hydrogels sensitive to temperature and/or pH of the surroundings are very interesting considering efficiency of immobilization and the ease of handling, which can be useful for the immobilization of the enzyme on the hydrogel, as well as for application of the immobilized enzyme as a biocatalyst.…”

“…The three-dimensional network can create an adequate and protective microenvironment for the enzyme protection and stability, enhanced by the involved support-enzyme interaction forces, such as electrostatic and hydrophobic interactions, that greatly influence the enzyme performance as biocatalyst. In the last years, several research groups studied the immobilization of the Candida rugosa lipase enzyme onto hydrogels [ 13 – 21 ]. The hydrogels sensitive to temperature and/or pH of the surroundings are very interesting considering efficiency of immobilization and the ease of handling, which can be useful for the immobilization of the enzyme on the hydrogel, as well as for application of the immobilized enzyme as a biocatalyst.…”

Stability of lipase immobilized on O-pentynyl dextran

“…3.1.1.3) are macromolecules of protein nature with molecular weights above 20,000 Da, and molecular size above 4 nm in diameter [1]. They are the most popular enzymes in biocatalysis, because they can be used in a variety of reactions due to their regio-and enantioselectivity [2][3][4][5]. During the last decade, lipases have gained more attention due to their applications in chemical and pharmaceutical industries in hydrolytic, esterification, transesterification, and various synthetic reactions in aqueous and organic media [6][7][8].…”

“…In the presence of hydrophobic support, the open form of the lipase becomes adsorbed thus shifting the equilibrium of ''open form'' and ''closed form'' in favor of the open form of the lipase [17,20]. Attachment on hydrophobic support normally increases the rigidity of the immobilized enzyme, making it more resistant to small conformational changes induced by heat, organic solvents and denaturing agents [4]. Due to a wide variety of conditions used, lipases are often easily inactivated and difficult to be separated from the reaction system for reuse which limits their industrial application [9].…”