In Staphylococcus aureus, 64 fatty acids could be separated by gas-liquid chromatography. The fatty acids consisted of normal, iso, and anteiso saturated fatty acids of from 10 to 21 carbon atoms. Of the total fatty acids, 2 to 4% were normal, iso, and anteiso monoenoic fatty acids. Positional isomers of the normal monoenoic fatty acids could be detected. The fatty acids could be extracted, leaving 1 to 2% of the total fatty acids in the residue. The proportions of the fatty acids in the residue and the total lipids differed significantly. The lipid extract contained less than 0.12% free fatty acid. Between 5 and 10% of the lipid fatty acids were associated with neutral lipids. The majority of the fatty acids were associated with the complex lipids: mono- and diglucosyl diglyceride, phosphatidyl glycerol, lysyl phosphatidyl glycerol, and cardiolipin. The proportions of the fatty acids changed markedly between bacteria grown anaerobically (no membrane-bound electron transport system) and those grown aerobically (containing a functional electron transport system). In each of the complex lipids, the proportions of the fatty acids, as well as the magnitude and direction of change in the molar quantity of the fatty acids per bacterium, changed dramatically between these growth conditions. Since the glucosyl diglycerides and phospholipids were formed from the same pool of diglyceride intermediates, the marked differences in fatty acids indicate that acyl transferase activities must be an important part of complex lipid metabolism in S. aureus.

Chromatography↗

PubMed1967

Extraction, characterization, and cellular localization of the lipids of Staphylococcus aureus.

Satisfactory extraction and assay procedures have been developed for the lipids of Staphylococcus aureus. The following lipids have been characterized in detail: the vitamin K(2), which is shown to exist as isoprenologues with side chains of 35, 40, and 45 carbon atoms; monoglucosyldiglyceride and diglucosyldiglyceride, which account for all the carbohydrate in the lipid extracts; the lysyl ester of phosphatidyl glycerol, phosphatidyl glycerol, and cardiolipin, which account for 98% of the phosphate in the lipid extract. The extraction procedure removes 98% of the total bacterial fatty acids. Acidification of the medium before harvest and refluxing in isopropanol are critical in the extraction procedure for the maximal recovery of lysyl-phosphatidyl glycerol and the glucolipids. The lipids have been shown to be a part of the same membrane as the respiratory pigments.

Carbonic Anhydrases↗

PubMed1967

Membrane lipid changes during formation of a functional electron transport system in Staphylococcus aureus.

Addition of oxygen to a culture of anaerobically growing Staphylococcus aureus results in the formation of a membrane-bound, functional electron transport system. With the shift to aerobic growth, there is at least a 15-fold increase in cytochrome a and at least a 55-fold increase in cytochrome oxidase o. At the completion of the shift to aerobic growth, the cytochrome levels equal those found in bacteria grown with aeration throughout the entire growth cycle. Cytochromes b(1) and o are formed first. Their synthesis slows when cytochrome a becomes detectable. Concentrations of cytochromes b(1) and sometimes cytochrome a increase late in the adaptive period. Concomitant with this is a decrease in the oxygen tension at which the rate of oxygen utilization becomes dependent on the oxygen concentration. During the shift to aerobic growth, the protoheme content increases ninefold, and all the protoheme can be accounted for in enzymatically reducible cytochrome b(1) and cytochrome oxidase o. Protoheme, but not a functional cytochrome system, is synthesized by anaerobically growing S. aureus. Heme a appears only after a period of aerobic growth. During the shift to aerobic growth, there is a 1.6-fold increase in the vitamin K(2) content, with an alteration in the ratios of the 35 and 45 carbon side chain isoprenologues. A twofold increase in phosphatidyl glycerol and a 1.6-fold increase in cardiolipin occur with the shift to aerobic growth. Lysyl-phosphtidyl glycerol remains essentially constant in this period. Concentrations of mono- and diglucosyl diglycerides increase coordinately 1.3-fold during the shift to aerobic growth at a 2.5 to 1 m ratio.

Cell Membrane↗