GC/MS identification and quantification of constituents of bacterial lipids and glycoconjugates obtained after methanolysis as heptafluorobutyrate derivatives.
Résumé
In previous papers (Pons et al., Anal. Biochem. 284 (2000) 201-216; Pons et al., J. Lipid Res. 43 (2002) 794-804), we reported that the GC/MS identification and quantification of almost all constituents of glycolipids could be obtained on the same sample in a single GC/MS analysis as heptafluorobutyrate derivatives of the products liberated using acid-catalysed methanolysis. The same type of data could be obtained on glycoproteins and proteoglycans (Pons et al., Biochemistry 42 (2003) 8342-8353). These experiments were performed on material from higher organisms and no evidence was provided that bacteria-specific constituents could be also identified and quantified. This manuscript reports that the GC/MS analysis of compounds liberated by acid-catalysed methanolysis as heptafluorobutyrate derivatives allows the simultaneous qualitative and quantitative determinations of pentoses, deoxyhexoses, hexoses, hexosamines, uronic acids, Kdo, Mur, heptose, Kdn and neuraminic acid and of most fatty acids (including hydroxylated fatty acids). This approach provides a way for obtaining fingerprints of bacterial constituents and quantification of the overall effect of gene inactivation or of culture conditions.