The cell surface associated phosphatase activity of Mycobacterium bovis BCG is not regulated by environmental inorganic phosphate

Non-specific phosphomonoesterase activities (alkaline phosphatase (EC 3.1.3 .1)and acid phosphatase (EC 3.1.3.2)) were examined at the cell surface of Mycobacterium bovis BCG. Using p-nitrophenylphosphate as the substrate, pea ks of phosphatase activity were detected at pH 6.0, pH 10.0 and pH 12.0, su ggesting the presence of one acid phosphatase and two alkaline phosphatases with distinct optimum pH values. Contrary to the situation observed in sev eral other microorganisms. the expression of these enzymes is not regulated by the environmental inorganic phosphate concentration. (C) 2001 Federatio n of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.