Penicillium expansum lipase-catalyzed production of biodiesel in ionic liquids

► [BMIm][PF6] is a superior solvent for Penicillium expansum lipase-catalyzed biodiesel production. ► Salt hydrates affect biodiesel production predominantly by specific ion effect. ► Different lipases show different resistance to methanol in different reaction systems. ► Penicillium expansum lipase is resistant to methanol in both ionic liquid and organic solvent systems.