Phospholipid Analogue Distribution of Prevotella pallens and Related Species Analysed by Fast Atom Bombardment Mass Spectrometry

The recently described species, Prevotella pallens, is related to, though distinguishable from, the Prevotella species P. intermedia and P. nigrescens. This study tested the hypothesis that P. pallens is distinct from both P. intermedia and P. nigrescens on the basis of phospholipid analogue distributions. Test strains were cultured and their lipids extracted using chloroform-methanol. Polar lipids were analysed by Fast Atom Bombardment-Mass Spectrometry (FAB MS) in negative ion mode. Both lower mass (carboxylate) and higher mass (phospholipid) peaks were measured for each mass spectrum before being statistically analysed. When Pearson Correlation Coefficients for strain pairs were subjected to average linkage cluster analysis, the resulting dendrogram grouped P. pallens strains together but separate from P. intermedia and P. nigrescens strains which clustered together. It is concluded that P. pallens strains are distinct from those of P. intermedia and P. nigrescens on the basis of phospholipid analogue distributions.