FATTY-ACID CONTENT IN WHOLE-CELL HYDROLYSATES AND PHOSPHOLIPID FRACTIONS OF PSEUDOMONADS - A TAXONOMIC EVALUATION

In a comparative taxonomic study, fatty acid contents of whole-cell hy drolysates and phospholipid, fractions of strains belonging to the pse udomonads were analyzed. Major fatty acids in all taxa were 16:0 and v arious isomers of 16:1 and 18:1. Fatty acid patterns of phospholipids were easily differentiated from whole-cell profiles by their absence o f hydroxylated fatty af ids. The latter constituents proved to be diag nostic markers for differentiation of the main phylogenetic lineages w ithin the pseudomonads (rRNA groups). Based on the presence or absence of three 3-hydroxy fatty acids, 10:0 3OH, 12:0 3OH, and 14:0 3OH, the majority of the strains could be allocated to one of the four rRNA gr oups (I-IV) studied. In general, rRNA group I organisms were character ized by the presence of 10:0 3OH and 12:0 3OH, rRNA group Il strains c ontained 14:0 3OH, group III strains contained 10:0 3OH and group IV s trains 12:0 3OH. A numerical analysis of the whole-cell fatty acid dat a yielded separate entities for all four rRNA groups. When using the f atty acid contents of phospholipids, no clear differentiation between rRNA group II and III taxa and rRNA group I organisms was obtained. Bo th approaches, however, yielded an analogous subgrouping of rRNA group I organisms which reflected their phylogenetic relationships.