Lipase activity was determined for culture supernatant according to Burkert et al. [40] and Padilha et al. [41]. The olive oil emulsion was prepared by mixing 25 ml of olive oil and 75 ml of 7% Arabic gum solution in a homogenizer for 5 min at 500 rpm. The reaction mixture containing 5 ml of emulsion, 2 ml of 10 mM phosphate buffer (pH 7.0) and 1 ml of the culture supernatant was incubated at 37 °C for 30 min in orbital shaker. The reaction was stopped by addition of 15 ml of acetone–ethanol (1:1, v/v), and the liberated fatty acids were titrated with 0.05 N NaOH. One unit of lipase activity was defined as the amount of enzyme, which liberated 1 µmol of fatty acid per minute. The protein content in the crude enzyme was determined by Lowry et al. [42] with BSA as a standard.