Original Article |
2007, Vol.29 Supplementary II : Grad. Res., pp.261-267
Optimization of lipase entrapment in alginate gel bead for palm olein hydrolysis
Pravit Jeamjounkhaw, Aran H-Kittikul, and Benjamas Cheirsilp
pp. 261 - 267
Abstract
Lipase from Pseudomonas sp. was entrapped by drop-wise addition of an aqueous mixture of alginate and the biocatalyst to hardening solution of CaCl2 for the purpose of palm olein hydrolysis. Effects of immobilization conditions including alginate concentration, CaCl2 concentration, enzyme concentration and bead size on immobilized yield, immobilized lipase activity and recovery of activity (specific activity ratio of entrapped lipase to free lipase) were investigated. An increase in alginate concentration raised immobilized yield, but decreased immobilized lipase activity and recovery of activity. CaCl2 concentration in the tested range of 50-200 mM had slight effects on immobilized yield, immobilized lipase activity and recovery of activity. In contrast to immobilized lipase activity, immobilized yield and recovery of activity decreased with increasing enzyme concentration. With increasing bead size, immobilized lipase activity and recovery of activity decreased due to mass transfer resistance whereas immobilized yield was unchanged. The optimum condition for lipase entrapment in alginate gel bead was alginate concentration at 2% (w/v), CaCl2 concentration at 100 mM, enzyme concentration at 30 U/ml and bead size at 2 mm. Under this entrapment condition, 8.11 U/ml of immobilized lipase was obtained with 95.2% of immobilized yield and 22.2% of recovery of activity.