Immobilization of CALB on lysine-modified magnetic nanoparticles: influence of the immobilization protocol

PAULA NICOLÁS; VERÓNICA LASSALLE; MARÍA LUJÁN FERREIRA

Bioprocess and Biosystems Engineering

Springer

Año: 2018 vol. 41 p. 171 - 184

1615-7591

Magnetic biocatalysts offer enormous advantagesover traditional ones. Their ability to be isolated bymeans of a magnet, in combination with their extensivereuse possibilities, makes them highly attractive and competitivefrom the commercial point of view. In this work,magnetic biocatalysts were prepared by immobilizationof Candida antarctica Lipase B (E.C. 3.1.1.3, CALB) onmagnetite?lysine nanoparticles. Two methodologies wereexplored tending to find the optimal biocatalyst in termsof its practical implementation: I?physical adsorption ofCALB followed by cross-linking, and II?covalent couplingof the lipase on the nanoparticles surface. Both proceduresinvolved the use of glutaraldehyde (GLUT) as cross-linkeror coupling agent, respectively. A range of GLUT concentrationswas evaluated in method I and the optimum one, interms of efficiency and operational stability, was chosen toinduce the covalent linkage CALB-support in method II. Thechosen test reaction was solvent-free ethyl oleate synthesis.Method I produced operationally unstable catalysts thatdeactivated totally in four to six cycles. On the other hand,covalently attached CALB (method II) preserved 60% of itsinitial activity after eight cycles and also retained 90% of itsinitial activity along 6 weeks in storage. CALB immobilizationby covalent linkage using controlled GLUT concentrationappears as the optimum methodology to asses efficientand stable biocatalysts. The materials prepared within this work may be competitive with commercially availablebiocatalysts