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.

Keywords

• alginate
• entrapment
• immobilization
• lipase
• Pseudomonas sp