L'6tude des lipides de cinq souches de Nocardia: N. caviae, N. erythropolis, N. farcinica, N. kirovani, N. sumatra a permis la caract6risation d'une gamme tr6s 6tendue d'acides nocardiques depuis C34H68Oa jusqu'~ C66H12403. Ces acides qui poss6dent tous une chaine lat6rale satur6e lin6aire de CxoH21 ~t C16H3~ et une chaine principale acyclique comprennent des compos6s homologues satur6s mono-, di-, tri-et t6tra6thyl6niques, le nombre de doubles liaisons augmentant avec le poids mol6culaire. La pr6sence d'acides nocardiques semble ~tre un crit6re g6n6ral du genre Nocardia bien que le poids mol6culaire soit assez variable suivant les esp&;es.
The lipids of five strains of Nocardia: N. caviae, N. erythropolis, N. farcinica, N. kirovani, N. sumatra have been examined; a large variety of nocardic acids has been isolated, ranging from Ca4H~sOa to C86H1~4Oa. These acids are mixtures of mono-, di-, tri-and tetraunsaturated compounds, the unsaturation being located in the main chain. The number of double bonds increases with increasing chain length. The branching at the ct position is a saturated, straight chain from C10H21 to CleHas. Nocardic acids are specific compounds of the genus Nocardia but the size of these acids varies with the different species.