Acylglucoses have been identified as major components of the soluble lipids of Corynebacterium diphtheriae, Mycobacterium smeginatis and BCG, grown in the presence of glucose. These have been purified and the structures determined. All contain one fatty acid per mole of glucose. Mass spectrometry of the methylated lipids and other methylation studies and periodate oxidation indicate that the fatty acids are estcrified to position 6 of the glucose. The major fatty acid of the acylglucose from C. diphtheriae andM. smegrnatis is corynomycolic acid (C,,H,,-CH-CH-COOH).

The phospholipids of Corynebacterium diphtheriae, Corynebacterium xerosis, C orynebacterium equi and Corynebacterium ovis were examined, largely by chromatographic procedures. In all of these, lipids of the phosphoinositide and mannophosphoinositide type were prominent. In contrast to the mycobacteria, the mannophosphoinositides of the corynebacteria were all dimannophosphoinositides; however, as in mycobacteria, these dimannophosphoinositides apparently occurred in the diacylated and triacylated forms-the tetraacylated component prominent in mycobacteria was absent. Phosphatidylethanolamine and phosphatidylserine were also absent. In Corynebacterium diphtheriae the major single phospholipid corresponded to phosphatidylglycerol: cardiolipin also appeared to be a major lipid. The fatty acids of the corynebacterial phospholipids were distinguished by the presence of branched chain isomers of medium chain length. The importance of phospholipids in the taxonomy of the actinomycetes and related eubacteria is discussed.

Corynebacterium diphtheriae gravis previously washed with acetone was extracted with chloroform-methanol-water. Lipids were dried, washed, converted into the sodium form and freeze-dried (Brennan, 1968). This phospholipid fraction was then subjected to the following treatments. Hydrolysis and chromatography in several solvent systems showed that the lipids were composed of inositol, mannose, glucose, glycerol and five amino acids. Ethanolamine and serine were absent from the ninhydrin-positive products. Deacylation of the lipid fraction and chromatography in two solvents showed the presence of glucose, trehalose, glycerophosphorylinositol, glycerophosphorylinositol dimannoside and a major unidentified product. About 1*2g. of the phospholipid fraction was

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