Phosphate metabolism in blue-green bacteria. V. Factors affecting phosphate uptake in Plectonema boryanum.

Plectonema boryanum requires approximately 5 days of exposure to a culture medium lacking phosphorus to induce the "polyphosphate overplus" phenomenon. At pH9, phosphate uptake is greatest both from normal culture medium and from dilute salt solutions. Phosphate uptake from dilute salt solutions was greatest when Na+ or K+ are combined with Ca2+ or Ca2+ and Mg2+. Cells starved of phosphorus in the presence of a high concentration of K+ or Ca2+ in the medium, and then allowed to take up phosphorus under the same conditions, assimilate more phosphorus than with other major ions.