ACYL PHOSPHATIDYLGLYCEROL - A MAJOR PHOSPHOLIPID OF CORYNEBACTERIUM-AMYCOLATUM

The type strain and several clinical isolates of Corynebacterium amyco latum were examined for lipid composition as a chemotaxonomic characte r for routine identification. The phospholipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol an d phosphatidylinositol mannosides, together with various unidentified compounds. One of them, accounting for 20-29% of total phospholipids, was purified and characterized as acyl phosphatidylglycerol by chromat ographic and spectrometric techniques. The acyl substituents on the ph osphatidyl moiety were characterized as tetradecanoyl, pentadecanoyl, hexadecenoyl, hexadecanoyl, heptadecenoyl, heptadecanoyl, octadecenoyl (the major one), and octadecanoyl. The acyl group on the polar head ( glycerol) was only octadecenoyl. Phospholipid analysis by thin-layer c hromatography of a collection of Corynebacterium strains proved that t his compound is widely; distributed, although it only represents a min or (2-9%) component among mycolic acid-containing species. Acyl phosph atidylglycerol can be considered as a useful chemical marker for the i dentification of C. amycolatum in addition to the absence of mycolic a cids.