title: Immobilization of Yarrowia lipolytica lipase--a comparison of stability of physical adsorption and covalent attachment techniques.
abstract: Lipase immobilization offers unique advantages in terms of better process control, enhanced stability, predictable decay rates and improved economics. This work evaluated the immobilization of a highly active Yarrowia lipolytica lipase (YLL) by physical adsorption and covalent attachment. The enzyme was adsorbed on octyl-agarose and octadecyl-sepabeads supports by hydrophobic adsorption at low ionic strength and on MANAE-agarose support by ionic adsorption. CNBr-agarose was used as support for the covalent attachment immobilization. Immobilization yields of 71, 90 and 97% were obtained when Y. lipolytica lipase was immobilized into octyl-agarose, octadecyl-sepabeads and MANAE-agarose, respectively. However, the activity retention was lower (34% for octyl-agarose, 50% for octadecyl-sepabeads and 61% for MANAE-agarose), indicating that the immobilized lipase lost activity during immobilization procedures. Furthermore, immobilization by covalent attachment led to complete enzyme inactivation. Thermal deactivation was studied at a temperature range from 25 to 45 degrees C and pH varying from 5.0 to 9.0 and revealed that the hydrophobic adsorption on octadecyl-sepabeads produced an appreciable stabilization of the biocatalyst. The octadecyl-sepabeads biocatalyst was almost tenfold more stable than free lipase, and its thermal deactivation profile was also modified. On the other hand, the Y. lipolytica lipase immobilized on octyl-agarose and MANAE-agarose supports presented low stability, even less than the free enzyme.
authors.affiliation: Instituto de Química, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Lab 549-2 and 536-B, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, Brazil.
authors.forename: Aline G
authors.initials: AG
authors.lastname: Cunha
authors.forename: Gloria
authors.initials: G
authors.lastname: Fernández-Lorente
authors.forename: Juliana V
authors.initials: JV
authors.lastname: Bevilaqua
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Destain
authors.forename: Lúcia M C
authors.initials: LM
authors.lastname: Paiva
authors.forename: Denise M G
authors.initials: DM
authors.lastname: Freire
authors.forename: Roberto
authors.initials: R
authors.lastname: Fernández-Lafuente
authors.forename: Jose M
authors.initials: JM
authors.lastname: Guisán
mesh_terms: D000327:Adsorption; D001665:Binding Sites; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D008049:Lipase / Q000737:chemistry*; D011485:Protein Binding; D013379:Substrate Specificity; D025062:Yarrowia / Q000201:enzymology*
chemical_list: D004800:Enzymes, Immobilized; D008049:Lipase