Catalase activity assay
The catalase activity of the soluble protein extracts was assayed as described previously. Briefly, 40-100 µL of extracts was assayed to 1.0 mL of 20 mM H2O2 in 50 mM KPi buffer (pH 7.0), and H2O2 decomposition was monitored at 240 nm (∑270=43.6 M-1 cm-1). One unit of catalase activity catalyzed the degradation of 1 µ mol of H2O2 per min and results are presented as the average ±SD catalase activity from three independent cultures (n=3).