Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide. 2 H2O2 = 2 H2O + O2 Active from pH 6.0 to 10.0. Activity decreases at temperatures above 55 degrees Celsius. Homodimer. Constitutively expressed. Inducible by oxidative stress in the exponential phase of bacterial growth. Belongs to the catalase family.