Modification of the activities of two different lipases from Candida rugosa with dextrans

Semipurified lipase from C. rugosa Type VII and another semipurified lipase obtained by fed-batch controlled fermenter conditions of C rugosa ATCC 14380 are modified using dextrans with different molecular weight (6,000; 10,000; 12,000; 25,000; 50,000 Da) Both lipases have different isoenzymes composition and sugar percentages. The lipase/dextran complexes are obtained by non-covalent or by covalent bonding of the sugar to the NH2 groups, of the protein. The modifications with dextrans increase the thermal stability of the biocatalyst compared to unmodified commercial lipase but not in the case of lipase obtained front C. rugosa ATCC 14380, This Ending is related to the amount of sugar covalently bonded to the parent enzyme, The catalysts are used in the enantioselective esterification of (R,S)-ibuprofen. The CRLS/dextran complexes are more active than the semipurified or commercial lipases from C. rugosa and they require a small amount of water to be active. The amount of water that must be added to obtain the maximum activity is different for-each biocatalyst. The modification with dextrans is very interesting for semipurified lipase from C rugosa but it is not useful for semipurified C. rugosa ATCC 14380 probably because this crude enzyme has high sugar content than commercial C rugosa lipase. (C) 2002 Elsevier Science Inc, All rights reserved.