LIPID COMPOSITION AND SYNTHESIS IN THE PLEUROPNEUMONIA-LIKE ORGANISM MYCOPLASMA GALLISEPTICUM

Tourtellotte, Mark E. (University of Connecticut, Storrs),Robert G. Jensen, George W. Gander, and Harold J. Morowitz . Lipid composition and synthesis in the pleuropneumonia-like organismMycoplasma gallisepticum . J. Bacteriol.86: 370–379. 1963.—A simple method of extracting lipids from cells ofMycoplasma gallisepticum by use of silicic acid columns is described. Proteolipids (peptides) extracted with chloroform-methanol (2:1) by other methods were not extracted with the lipid by this method, nor were proteins and nucleic acids. Fractionation of lipids ofM. gallisepticum demonstrated the presence of saturated hydrocarbons, free fatty acids, cholesterol, cholesterol esters, di- and triglycerides, phosphatidic acids, cephalins, inositides, phosphatidyl choline, and sphingomyelin. The fatty acid composition of the various fractions was also determined. The positive identification of cholesterol and cholesterol esters in this organism by chromatography, melting point, and infrared spectroscopy confirms reports by others that cholesterol is present in the pleuropneumonia group of microorganisms. The incorporation of P32 orthophosphate into four phospholipid fractions, of oleic acid-1-C 14 into neutral and phospholipids, and cholesterol-4-C 14 into cholesterol esters clearly demonstrated the ability ofM. gallisepticum to synthesize these lipids from simpler compounds. Between 70 and 80% of the lipid of this organism was found in the membrane.