Rôle du Tween-80 utilisé dans la culture des corynébactéries cutanées (groupe JK) sur la composition en acides gras cellulaires

Abstract

This study of 8 strains of cutaneous corynebacteria, including 5 strains of «JK corynebacteriaå, concerns the fatty acid composition of cells grown in the presence or not of Tween 80, which enhances their growth rate. The fatty acid methyl esters were analysed by gas-liquid chromatography. The fatty acid profile of the 8 strains agreed with the general pattern of the genus Corynebacterium, with major amounts of palmitic acid (C16:0) and oleic acid (C18:0) and with only trace amounts of 10-methyl octodecanoic acid (tuberculostearic acid). Iso and anteiso branched acids were not present. The 5 strains had high levels of stearic acid (C18:0). When cells were grown in the presence of Tween-80, the fatty acid composition was modified for all strains: their profiles showed high levels of oleic acid (C18:1) and smaller quantities of palmitoleic acid (C16:1). These results confirm the advantage of fatty acid composition for identification of Corynebacteria, and particularly for cutaneous strains, and emphasize the influence of the culture medium, especially that of Tween-80.