Bacillus subtilis vegetative catalase is an extracellular enzyme

Bacillus subtilis cells in the stationary growth phase secrete the vegetative catalase KatA when grown in a rich culture medium. The bacteria requires KatA activity to protect itself completely from oxidative stress and H2O2. Cytoplasmic catalase activity alone does not provide protection from oxidative stress. This suggests that the vegetative catalase is an extracellular enzyme rather than an endocellular enzyme. The bacterial cells present in a sporulation-inducing medium do not produce any catalase.