Carbons from choline present in the phospholipids of Pseudomonas aeruginosa

Abstract

The phospholipid composition of Pseudomonas aeruginosa grown in a mineral medium with choline as the carbon source was: phosphatidylethanolamine, 71.6+/-1.4%; phosphatidylglycerol, 11.8+/-0.4%; diphosphatidylglycerol, 0.8+/-0.4%; phosphatidic acid, 2.4 +/- 0.6%; lysophosphatidylethanolamine, 1.6 +/- 0.3%; phosphatidylcholine 7.9 +/- 0.3%; lysophosphatidylcholine, 3.9 +/- 0.7%. The molar ratio between the acidic and the neutral phospholipids was 0.18. Radiolabeling experiments with [methyl-C-14]choline or [1,2-C-14]choline carried out in cell suspension from bacteria that were grown in the presence of choline as the sole carbon source demonstrated that the carbons of the N-methyl groups of choline contributed to the synthesis of fatty acids while the carbons comprising the backbone of choline were used for the synthesis of glycerol.