Localization of alkaline phosphatase in Bacillus intermedius cells

Alkaline phosphatase, an enzyme secreted by Bacillus intermedius S3-19 cell s to the medium, was also detected in the cell wall, membrane, and cytoplas m. The relative content of alkaline phosphatase in these cell compartments depended on the culture age and cultivation medium. The vegetative growth o f B. intermedius on 0.3% lactate was characterized by increased activity of extracellular and membrane-bound phosphatases. The increase in lactate con centration to 3% did not affect the activity of membrane-bound phosphatase but led to a decrease in the activity of the extracellular enzyme. Na2HPO4 at a concentration of 0.01% diminished the activity of membrane-bound and e xtracellular phosphatases. CoCl2 at a concentration of 0.1 mM released memb rane-bound phosphatase into the medium. By the onset of sporulation, phosph atase was predominantly localized in the medium and in the cell wall. As is evident from zymograms, the multiple molecular forms of phosphatase varied depending on its cellular localization and growth phase.