The fatty acids present in the total hydrolysates of several gliding bacteria (Myxococcus fulvus, Stigmatella aurantiaca, Cytophaga johnsonae, Cytophaga sp. strain samoa and Flexibacter elegans) were analyzed by combined gas-liquid chromatography and mass spectrometry. In addition to 13-methyl-tetradecanoic acid, 15-methyl-hexadecanoic acid, hexadecanoic acid, and hexadecenoic acid, 2and 3-hydroxy fatty acids comprised up to 50% of the total fatty acids. The majority was odd-numbered and

more »

... nched. Small amounts of even-numbered and unbranched fatty acids were also present. Whereas 2-hydroxy-15-methylhexadecanoic acid was characteristic for myxobacteria, 2-hydroxy-13-methyltetradecanoic acid, 3-hydroxy-13-methyl-tetradecanoic acid, and 3-hydroxy-15methyl-hexadecanoic acid were dominant in the Cytophaga-Flexibacter group. heating the sample with boron trifluoride-methanol reagent (14% wt/vol Serva, Heidelberg) (16). Modification of fatty acid methyl esters. Hydrogenation of unsaturated methyl esters was performed by using nascent hydrogen (prepared with Zn-4 N HCI) with the aid of Pd on charcoal (10%; E. Merck AG, Darmstadt, Germany) as a catalyst. The 852 on May 9, 2020 by guest