YEAST EICOSANOIDS .1. THE DISTRIBUTION AND TAXONOMIC VALUE OF CELLULAR FATTY-ACIDS AND ARACHIDONIC-ACID METABOLITES IN THE DIPODASCACEAE AND RELATED TAXA

The cellular long-chain fatty acids of 34 strains representing the genera Clavispora, Dipodascopsis, Dipodascus, Geotrichum, Lodderomyces and Schivanniomyces were extracted and analyzed as methyl esters by gas chromatography. The fatty acid composition and coenzyme Q systems of these yeasts and others from literature were compared in a coordinated scheme and their taxonomic positions assessed. In contrast to other families of the Endomycetales, the hyphomycete-like genera of the Dipodascaeae showed a remarkable degree of homogeneity regarding fatty acid composition and coenzyme Q system. The hyphomycete-like genera of the Dipodascaceae could be distinguished from the superficially similar Dipodascopsis by the absence of linolenic acid and their ability to grow in the presence of 1 mM aspirin. Both species representing Dipodascopsis were able to produce aspirin sensitive 3-hydroxy arachidonic acid (3-HETE) from arachidonic acid while species representing Dipodascus, Galactomyces and Geotrichum were unable to do so. These criteria correlate well with known taxonomic criteria which differentiate between the taxa concerned.