INVESTIGADORES
MAMMARELLA Enrique Jose
congresos y reuniones científicas
Título:
Improving the properties of chitosan as support for the covalent multipoint immobilization of chymotrypsin
Autor/es:
ADRIANO, WELLINGTON; MENDONÇA, DANY; RODRIGUES, DASCIANA; MAMMARELLA, ENRIQUE; GIORDANO, RAQUEL
Lugar:
Benalmádena, Málaga, España
Reunión:
Simposio; XXI Simposio Iberoamericano de Catálisis (SICat 2008); 2008
Institución organizadora:
Sociedad Española de Catálisis (SECAT) y Universidad de Málaga (UMA)
Resumen:
Several strategies were tested to improve the covalent multipoint attachment of chymotrypsin onchitosan. Hybrid gels with different internal structure were obtained using sodium alginate, gelatin or k-carrageenan and different activating reactant. Addition of microorganisms to the hybrid polymer, followed by cellular lyses, increasing of the immobilization reaction time and the effect of final derivative reduction were also tested. The half-life of derivative increased from 0.57 hours (at 55°C), for the enzyme immobilized in chitosan 2.5% activated with glutaraldehyde at pH 7.0, 4°C, for 2h to 7.8 hours (at 65°C), for chymotrypsin immobilized in  chitosan2.5%-carrageenan2.5%, with 5% of S.cerevisiae followed by its removal after gel formation, epichlorohydrin activated, immobilization for 72 hours at pH10.05 (25°C) and reduced. This best derivative was around 9900-fold more stable than free enzyme. A maximum load of 40 mg chymotrypsin.g-1 beads was achieved. The quantification of aldehyde and oxirane groups in the support and lysine residues of the enzyme involved in the immobilization, as well as analysis of SEM images, agree with the obtained results.