부산대학교 도서관

This work evaluated the capacity of protic ionic liquid (PIL) used as an additive to enhance the immobilization of lipase from Bacillus sp. in a sol-gel matrix. The immobilized derivatives were characterized with respect to the specific surface area, adsorption-desorption isothermic values, pore volume and size by nitrogen adsorption, thermal analysis and full recovery of activity. The lipases were immobilized using different PILs of the same cation ( N-methylmonoethanolamine) and different anions (acetate, propionate, butyrate and pentanoate). The results showed that the total recovery of activity for the samples encapsulated in the presence of PIL was always higher than those without the encapsulated additive ( total activity yield, Ya = 71%), particularly when using the more hydrophobic nature PILs ( Ya = 305%), and at concentrations of 0.5 mass%. The positive effect of using PILs was also observed in the formation of the porous structure of the biocatalysts, as well as the increases in surface area (78 to 278 m g) and pore volume (0.018 to 0.414 cc g). The thermal analysis has revealed the key role of water content on the hydration shell of the enzyme caused by the change in the alkyl chain of ionic liquids, showing that the PILs are an excellent alternative for immobilization processes. [ABSTRACT FROM AUTHOR]