Taxonomic significance of hydroxy fatty acids in myxobacteria with special reference to 2-hydroxy fatty acids in phospholipids.

Abstract

The cellular hydroxy fatty acid composition of myxobacteria was investigated. Strains tested included 7 strains of Myxococcus species and one strain of Archangiunr, together with other gliding bacteria, 2 strains of Cytophaga species, as reference bacteria. Myxobacteria commonly had 2-hydroxy and 3-hydroxy fatty acids as the hydroxy fatty acid components. The hydroxy fatty acid profile of myxobacteria was characterized as follows: 2-hydroxy-l5-methylhexadecanoic acid (2-OH iso C17:0) is the major hydroxy fatty acid component. In lipids extractable with chloroform/methanol (extractable lipids), 2-hydroxy fatty acids were the major hydroxy fatty acid components. In lipids non-extractable with chloroform/methanol (bound lipids), both 2-hydroxy and 3-hydroxy fatty acids appeared. This hydroxy fatty acid profile was different from that of Cytophaga species which commonly had 3-hydroxy-l3-methyltetradecanoic acid (3-OH iso C15:0) and 3-hydroxy-l5-methylhexadecanoic acid (3-OH iso C17 :o) as the major hydroxy fatty acids, and these 3-hydroxy fatty acids occurred in both extractable and bound lipids. The myxobacteria were characterized also by phospholipid components in the extractable lipids. Phosphatidylethanolamine was the major phospholipid. It consisted of two types, one containing only non-hydroxy fatty acids and the other containing approximately 50% hydroxy fatty acids in the total fatty acids. The myxobacteria were characterized by the above hydroxy fatty acid profile.Inc.,

Plesiocystis pacifica gen. nov., sp. nov., a marine myxobacterium that contains dihydrogenated menaquinone, isolated from the Pacific coasts of Japan

“…Strains SIR-1 T and SHI-1 possessed similar fatty acid profiles, with iso-C 15 : 0 (32?3-35?6 % of total fatty acids) and iso-C 16 : 0 (13?5-14?6 %) as the major components, in accord with those of known species of myxobacteria (Yamanaka et al, 1988). A long-chain PUFA (C 20 : 4 ) was also detected in substantial amounts (14?1-17?5 %).…”

Haliangium ochraceum gen. nov., sp. nov. and Haliangium tepidum sp. nov.: Novel moderately halophilic myxobacteria isolated from coastal saline environments.

“…While palmitic acid (n-C16 : 0) was most abundant in SMP-2, iso-branched acid (iso-C16 : 0) predominated in SMP-10. Anteisobranched acids were also detected, which distinguished the marine isolates from other myxobacteria (Fautz et al, 1979;Yamanaka et al, 1988). No hydroxy acids were detected.…”

Taxonomic and Phylogenetic Studies on a New Taxon of Budding, Hyphal Proteobacteria, Hirschia baltica gen. nov., sp. nov.

“…Hydroxy fatty acids were prepared by using acid methanolysis with toluene-methanolconcentrated sulfuric acid (5 : 5 : 0.2 vol/vol/vol) at 50°C overnight (Collins, personal communication), followed by the treatment described by Minnikin et al (35,36). Hydroxy fatty acid methyl esters were analyzed by gas-liquid chromatography (type OV-1; 200 to 270°C; 4"C/min) and were identified by gas-liquid chromatography-mass spectrometry (60).…”