Differentiation between gram-negative anaerobic bacteria by pyrolysis gas chromatography of lipopolysaccharides

Lipopolysaccharides extracted by phenol-water from nine strains of Gram-positive anaerobic bacteria (Bacteroides. Fusobacterium and Veillonella), have been examined by means of pyrolysis gas chromatography. Lipopolysaccharides were fragmented into a group of low molecular weight components and four characteristic high molecular fractions probably consisting of hydrocarbons from the lipid part of the material. The latter fractions were specific for each of the genera tested. At the species level characteristic differences were also found although a limited number of strains were tested. Due to the high reproducibility of the technique, the potential of using the method in differentiating Gram-negative anaerobic bacteria was indicated.