Deoxyribonucleic Acid Base Composition in Yeasts

Sally A. Meyer, H. J. Phaff
1969 Journal of Bacteriology  
The deoxyribonucleic acid base composition of 15 species of yeasts was determined to obtain further clues to or supporting evidence for their taxonomic position. Species examined belonged to the genera Saccharomyces, Debaryomyces, Lodderomyces, Metschnikowia, and Candida. The range of moles per cent guanine plus cytosine (GC content) for all yeasts examined extended from 34.9 to 48.3%. The sporogenous species and the asporogenous yeasts spanned the range with 36.6 to 48.3% GC and 34.9 to 48%
more » ... respectively. Three Saccharomyces species (S. rosei and related species) exhibited significantly higher GC contents than S. cerevisiae, whereas the fermentative species D. globosus revealed a %GC more aligned to the S. rosei group than to the nonfermentative D. hansenii. Similar GC contents were demonstrated by L. elongasporus and its proposed imperfect form C. parapsilosis. The range of GC contents of various strains of three Metschnikowia species studied was 6.1%, with the type strain of M. pulcherrima having the highest GCC content (48.3%) of all of the yeasts examined. The contribution of studies on deoxyribonucleic acid (DNA) base composition to the understanding of systematics and taxonomy of bacteria is well established (7) . Similar information on other organisms is available only to a limited extent. Although Belozersky and Spirin (2), in their review of nucleic acids in microorganisms, suggested that an investigation of the DNA base composition of fungi from the viewpoint of speciation would be of significant value, only a few brief surveys (11, 16, 19, 20) have been made. These studies supported the usefulness of determining DNA base composition in fungal taxonomy. In the most extensive study thus far reported, Storck (14) examined 30 species of fungi for their DNA base composition. Included in his investigation were representatives of the four major classes of fungi. For the first time in such a study, 14 species of yeast of 11 different genera were among the fungi examined. The four classes of fungi demonstrated a range of guanine plus cytosine (GC) contents of from 38 to 63%. The Zygomycetes (38 to 48%) and Ascomycetes (38 to 54%) were represented at the lower end of this range, whereas the Deuteromycetes (47 to 62%) and the Basidiomycetes (44 to 63 %) were found at the upper level. Hemiascomycetidae, to which the ascosporogenous yeasts belong, were located in a narrower range of 39 to 45% GC. Among the nonascosporogenous yeasts, the relatively high GC contents of a species of Cryptococcus (55%) and a species Rhodotorula 52
doi:10.1128/jb.97.1.52-56.1969 fatcat:5x2bixw52fcbfcwqrt4qegavbi