System. Appl. Microbiol. 18,410-424 (1995) © Gustav Fischer Verlag, Stuttgart· Jena . New York Lipid Composition and DNA Band Patterns In the Yeast Family Lipomycetaceae E. L. JANSEN VAN RENSBURG, J. L. F. KOCK, D. J. COETZEE, A. BOTHA, and P. J. BOTES Department of Microhiology and Biochemistry, University of the Orange Free State, Bloemfontein, South Africa Received April 13, 1995 Summary The distrihution of Dl\:A hand patterns (karyotyping) as well as the ())3 and (1)6 fany acids (FAs) present in the neutral, phospho- and glycolipid fractions in the teleomorphic family of the Lipomycetaceae <lnd related anamorphs in Myxozyma, were determined. Improved DNA band separation was obtained when compared with the band patterns reported for this family by earlier workers. A similar trend in the distrihution of the DNA band patterns was, nevertheless, observed in this investigation. In a study which included the analyses of 69 strains representing 19 species, we found that the genus Dipodascopsis, regarded by some as the ancestral representative of this family, produced heavy DNA bands (larger than 1300 kb), while the presumed, more recently evolved representatives assigned to M)'xozyma were charac- terized hy much smaller and more numerous bands. In terms of total FA composition of these yeasts, it was found th3t all representatives of the genus Lipomyces investigated, produced the OJ3 polyunsaturated FA, u-linolenic acid (18: 3) while some Z)'gozyma and Myxoz),ma species were unable to produce this FA. Bab;el'ia anomala was characterized by only two DNA bands larger than 1300 kb and the presence of 18: 3. Seventy four strains, representing 20 teleomorphic species of the Lipomycetaceae and related anamorphs were further analysed for their lipid content when cultivated in a medium containing a high C: N ratio. Under these conditions all the strains were capable of producing the w3 series of 18: 3 FAs in their polar fractions. Contrary to the belief that the Lipomycetaceae and related anamorphs may all be oleaginous, it was found in this study that only members of the genera Bab;evia and Lipo/n)'ces (excluding L ;aponims) actually produce large quantities of lipid. Oleaginicity and the palmitoleic acid (16: 1) content in the nelltr3l lipids, proved to be useful in distinguishing between the genera Bab;evia, Dipodas- copsis and Lipomyces (with the exclusion of L ;aponicus) and Z)'goZ)'ma. FA and Co Q composition provides additional biochemical evidence for the postulated phylogenetic connexions between M)'xozyma and the teleomorphic genera Lipo11lyces 3nd Zygoz)'ma. It was shown that in terms of oleaginicity, p31mitoleic acid content and DNA band patterns, Bab;evia anomala and Lipomyces ;aponicus occupy isolated positions within the family. Key words: Lipomycetaceae - DNA Band Patterns - FA Composition - Taxonomy Introduction The presence of the w3 and (t)6 fatty acids (FAs) in fungi is well established. In an extensive survey, which included the FA compositions of hundreds of different fungi, Van der Westhuizen (1994) concluded that FAs are particularly useful to discriminate between higher taxa. Cottrell and Kock (1989) studied the total FA composi- tion of several lipomycetaceous yeasts and found these· organisms to contain FAs typical of the Dikaryomycota. Moreover, Cottrell and Kock (1990) found informative trends when FAs and DNA band patterns of members of this family were compared. According to their results, species characterized by similar DNA band patterns re- vealed a similarity in their FA profiles. They also suggested that FAs and DNA band patterns are possibly indicative of a phylogenetic development in the yeast family Lipomy- cetaceae from Dipodascopsis (a complex hyphal form pro- ducing a-linolenic acid or 18: 3 and one large DNA band) through Lipomyces (with diverse ascosporal surface or-