Enhanced activity of Mucor javanicus lipase in polyoxyethylene sorbitan trioleate containing microemulsion-based organogels

The efficacy of polyoxyethylene sorbitan trioleate (Tween 85) addition on the activity of Mucor javanicus lipase was investigated in sodium bis(2-ethylhexyl) sulfosuccinate (AOT) microemulsion-based organogels (MBGs). Gelatin was used as the gelling component of the MBGs. The maximal reaction rate was obtained at an AOT:Tween 85 molar ratio of 10:1. Under a fixed molar ratio system of AOT:Tween 85 = 10:1, the reaction rate also attained a maximum at a WG (=[H2O]/[AOT + Tween 85] in MBG phase) value of 100 and an AOT concentration of 150 mM. The reaction proceeded under a reaction-controlled regime, and the reaction rate for the AOT/Tween 85 mixed system was about 2-fold higher than that for the AOT single system. The lipase activity was well maintained for 10 days and recovered by contacting the MBGs with concentrated amphiphile solutions.