Immobilization of lipase from Pseudomonas sp. Lp1 by different techniques

摘要

Psudomonas sp.Lp1 extracellular lipase was immobilized by three different techniques such as entrapment in alginate, physical adsorption using celite, and ionic binding to two different kinds of cation exchangers Amberlite IR120 (Na+) and IRCSO (H+). The objective of this study was to develop a suitablemethod for immobilizing lipase. The stability of the free and immobilized lipase at different pH, Temperature and Metal ions and its storage stability were also evaluated.Among the three techniques, the immobilization by ionic binding with the cation exchangers -Amberlite IR120 (Na+) and IRCSO (H+) showed greater efficiency of 73% and 78% respectively. The immobilized lipase showed improved stability when compared to free lipase. The stability of lipase in celite,Amberlite IR120 (Na+) and IRCSO (H+) at pH8.0was 87.3%, 94.6%and 96.7%respectively.The immobilizates -Amberlite IR120 (Na+) and IRCSO (H+) showed 65%and 68%of enzyme activity even at 60oC. The activity retained by immobilized lipase by ionic bindingwithAmberlite resin IR120 (Na+) andAmberlite IRCSO (H+) in the presence of Ca2+ ion was higher (152%and 140%) than any other methods of immobilization respectively. The ionic bindingmethod of immobilization retained 70%of its original activity till 20 days of storage at 4oC.