Regulation of Lipid Synthesis in Bradyrhizobium japonicum: Low Oxygen Concentrations Trigger Phosphatidylinositol Biosynthesis

Lowering oxygen tension in free-living Bradyrhizobium japonicum resulted in a dramatic switch of membrane chemistry in which phosphatidylcholine, the predominant lipid in aerated cultures, was no longer synthesized and phosphatidylethanolamine became the major lipid. Besides this change, phosphatidylinositol, a typical plant lipid rarely found in bacteria, was also synthesized.