STUDY OF THE STABILIZATION OF PURE LIPASES - COMPARISON OF 2 DIFFERENT LIPASE-MICROGEL DERIVATIVES

The immobilization/stabilization of pure and very labile lipases was s tudied. Two types of lipase-microgels derivatives, which may be used i n aqueous and/or organic media were designed and optimized. The first type consisting in the covalent linkage of the protein to the surface of a previously formed microgel. The second type was obtained in a rev erse micellar system of AOT. The lipase was microencapsulated into the acrylic microgels formed after a polymerization process carried out i n the micellar droplets. In this case, a crosslinking agent was simult aneously used to enhance the protein rigidity. Due to the distinct lip ase localization the two microgel derivatives differ in their activiti es and stabilities: the microgel with the lipase at its surface had a similar activity and stability as the native lipase, while an importan t reduction of the conformational mobility of the protein was found wh en the lipase was microencapsulated, and it gave rise to a high stabil ization factor. Thus, a new immobilization method which stabilizes by 352 times at 45 degrees C the pure isolipase B from Candida cylindrace a is described. These results were also better than those of the crude lipase stabilization by multipoint attachment to agarose gels.