SELECTION OF A SUPPORT FOR IMMOBILIZATION OF A MICROBIAL LIPASE FOR THE HYDROLYSIS OF TRIGLYCERIDES

Baterial lipase from Staphylococcus carnosus (pLipMut2) has been immob ilized on various supports in order to determine a suitable immobiliza tion technique in terms of activity and stability, when utilized for t he hydrolysis of tributyrin. The hydrophobic materials PEA Eupergit an d PEA Eupergit 250L prooved to be appropriate supports, when the enzym e was crosslinked with glutaraldehyde after adsorption. No desorption of the immobilized enzyme occured during operation. The pore size of t he support has a strong effect on the activity but does not influence stability. The initial activity for immobilized and soluble lipase is found to follow the Arrhenius equation at low temperature, where mass transfer does not affect reaction kinetics. Activation energies for so luble and immobilized lipase were evaluated to be 21.7 kJ mol(-1) and 60.8 kJ mol(-1), respectively. Operational stability was studied in a packed bed recirculation reactor. Thermal desactivation followed first order kinetics with a half-life of 1340 h at 10 degrees C. Model calc ulations for productivity showed, that optimal temperatures for high p roductivity are well below the temperature of maximal activity.