Dihydroxy and monohydroxy fatty acids in Legionella pneumophila

Abstract

Five strains of L. pneumophila were examined for the presence of hydroxy fatty acid. The cellular distribution of the fatty acids was also determined, as was the variation of hydroxy acid production on 5 growth media. The strains tested all produced .apprx. 5 mol% of hydroxy fatty acid, most of which was found in the nonextractable, alkali-stable, acid-labile (wall-associated, amide-linked) fraction. Three major hydroxy acids were found, along with several minor components. The major hydroxy acids were analyzed by TLC, GLC, mass spectrometry and IR spectrophotometry. These compounds were tentatively identified as 3-hydroxy-12-methyltridecanoate, 3-hydroxy-n-eicosanoate and a novel dihydroxy acid, 2,3-dihydroxy-12-methyltridecanoate. The total amount of hydroxy acid produced and the profile of the hydroxy acids remained relatively unchanged with respect to strain and growth medium.