Immobilisation studies and catalytic properties of microbial lipase onto styrene-divinylbenzene copolymer

摘要

Microbial lipase from Candida rugosa was immobilised by physical adsorption onto styrene-divinylbenzene (STYDVB) copolymer. Two different coupling media were evaluated: aqueous solution (sodium phosphate buffer) and organic solvent (heptane). The choice of the immobilisation medium had a large effect on the hydrolytic and synthetic lipase activities. Better results were found when the coupling procedure was performed in the presence of heptane. The effects of enzyme loading and support capacity regeneration were also studied. Both, free and immobilised lipases were characterised by determining the activity profile as a function of pH, temperature and thermal stability. For the immobilised lipase, operational and storage stabilities were also determined. Operational stability tests indicated that a small enzyme deactivation occurs 12 consecutive batches of 24h each. Such results revealed good potentifal for recycling under nonaqueous system.