Sodium-controlled Coupling of Respiration to Energy-linked Functions in Pseudomonas stutzeri

Abstract

Summary: In the presence of K+, Na+ enhanced respiration and activated cellular motility and transport of K+, amino acids and phosphate in Pseudomonas stutzeri. Inorganic phosphate taken up was rapidly esterified to nucleoside triphosphates and diphosphates. Respiration and phosphate transport showed cooperative responses to Na+ which increased with temperature. Respiration was more sensitive to polymyxin B in the presence of Na+. Dinitrophenol and carbonyl cyanide p-trifluoromethoxy-phenylhydrazone stimulated respiration when either Na+ or K+ was absent, but not in the presence of both cations. Therefore, Na+ is essential for the cytoplasmic membrane of P. stutzeri to perform energy-linked functions coupled to respiration.