Partial purification and biochemical characterization of extracellular lipase from Azospirillum sp. JG3 bacteria

Abstract

Abstract. An extracellular lipase from Azospirillum sp.JG3 bacteria was partially purified by ammonium sulfate fractionation. Production of crude extract lipase in Nutrient Broth medium fortified with 1 % olive oil as inducer, fractionation of lipase using ammonium sulfate, and characterization of the highest specific activity of lipase fraction have been achieved in this study. The ammonium sulfate lipase fraction which has highest specific activity is F60 with its value is 12,283.33 U/mg protein. The optimum lipase activity of F60 was achieved at 40° C and pH 7.0. The addition of 1.0 mM EDTA strongly decreased its activity. It considered that this lipase was a metalloenzyme. The addition of 1.0 mM Ca 2+ solution showed that this metal ion increased lipase activity, it indicated that Ca 2+ ion is an activator of this lipase. Whereas addition of Mg 2+ , Zn 2+ , Co 2+ , and Cu 2+ metal ions decreased its activity. Effect of surfactants and commercial detergents addition towards lipase activity showed that all treatments decreased the activity.