|Middelhoven, Wouter - WAGENINGEN UNIV., NL|
Submitted to: Antonie Van Leeuwenhoek
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 2, 2001
Publication Date: January 20, 2003
Citation: MIDDELHOVEN, W.J., KURTZMAN, C.P. RELATION BETWEEN PHYLOGENY AND PHYSIOLOGY IN SOME ASCOMYCETOUS YEASTS. 2003. V. 83. P. 69-74. Interpretive Summary: Genetic relationships among yeasts, as well as other living organisms, can be estimated from substitutions (differences) in the gene sequences of their genetic material (DNA). This study tests the idea that closely related yeasts will have more similar growth characteristics than species that are only distantly related. The work showed that widely seen characteristics such as sugar fermentation are common to both closely and distantly related species, but that ability to grow on certain unique chemicals (e.g., methanol, imidazole, isobutanol) is shared by only small groups of closely related species. If a yeast is needed to modify an unusual agriculturally important chemical in an industrial fermentation process, it is likely that closely related species can also grow on this compound and could be tested as potentially better choices for a particular requirement. In contrast, distantly related species are unlikely to have the unique metabolic properties needed.
Technical Abstract: The question of whether yeasts with similar physiological properties are closely related has been examined using recently published phylogenetic analyses of 26S domain D1/D2 rDNA nucleotide sequences from all currently recognized ascomycetous yeasts. When apparently unique metabolic pathways are examined, some correlations between physiology and rDNA phylogeny are evident. Data were obtained experimentally and from the literature. Utilization of imidazole as a sole nitrogen source seems to be restricted to genera of the Lipomyces clade (Lipomyces, Myxozyma and Zygozyma). Starch-like compounds are produced by the Lipomyces clade, by some members of the 'Archiascomycete clade' (Protomyces), by the Euascomycetes Emericella nidulans, Neurospora crassa and Oosporidium) and by many basidiomycetous yeasts, most of them in the Tremelloidea. Another example concerns methanol assimilation. Most Candida and Pichia species that are able to assimilate methanol as the sole carbon source are in a clade delimited by C. nanospora and C. boidinii. Exceptions are P. capsulata and P. pastoris which are phylogenetically separated from the other methanol-assimilating yeasts.