A time-course respiratory inactivation associated with Azobacter cells deprived of Mg++.

It has been reported (Gunter, 1954) that Mg++ prolongs the viability of various microorganisms suspended in potassium phosphate buffer, and that celLs of Azotobacter are singularly affected by MgSO4. It was previously observed (Goucher and Kocholaty, 1954) that MgSO4 is required for the oxidation of several organic compounds by whole cells of Azotobacter agile. Data presented in this communication indicate that Mg++ is essential not only for the oxidative function of the cell, but may be also of significance in the maintenance and function of permeability and transport mechanisms.