Immobilization of keratinolytic serine protease from Purpureocillium lilacinum LPS # 876 on activated chitosan beads. study of the cross-linker

CAVELLO, IVANA; ROJAS, LORENA; CONTRERAS ESQUIVEL, JUAN CARLOS; CAVALITTO, SEBASTIÁN

Fos do Iguaçu

Congreso; XIX Simpósio Nacional de Bioprocessos-X Simpósio de Hidrólise Enzimática de Biomassa; 2013

A keratinolytic serine protease from Purpureocillium lilacinum LPS # 876, purified from submerged cultures, using hair waste as substrate, was immobilized on chitosan beads. Glutaraldehyde and genipin were tested as potential cross-linkers. Immobilization conditions were optimized by one-factor at-a-time strategy. Yields of immobilized enzyme obtained from this study were over 90% for all concentrations of glutaraldehyde tested and with a maximum (92%) for genipin. The enzyme loading capacity was about 27 % for glutaraldehyde and was independent from the cross-linker concentration. But, when genipin wastested, this parameter increased as the concentration of the cross-linker was increased and the temperature was decreased. Although yields of immobilized enzyme were similar for both cross-linkers, enzyme activity on chitosan beads was higher when genipin was used as crosslinker. For this reason, genipin was selected as the cross-linker for keratinase immobilization. The immobilized keratinase retained 100% of its initial activity after 3 cycles of azocasein hydrolysis.