The yeastKluyveromyces africanus nov. spec. and its phylogenetic significance

Summary A new budding yeast species isolated from soil is described. Its outstanding features are, firstly, the formation of asci containing up to sixteen long oval to reniform ascospores and, secondly, a fermentative as well as oxidative metabolism. The assimilation of nitrate is absent and no pseudomycelium is formed. The taxonomic position of the yeast is discussed and it is pointed out that, due to its exceptional ascospore number (1–16), it cannot be classified in any of the existing fermentative genera of theEndomycetaceae (in sensu Lodder et Kreger-van Rij). The reniform shape of its ascospores indicates, however, its close relationship with the multispored genusKluyveromyces, on the one hand, and the newly proposed one to four-spored genusDekkeromyces on the other. The species is provisionally classified as aKluyveromyces species,Kluyveromyces africanus nov. spec., until further information regarding its sexual characteristics becomes available. By virtue of its more or less intermediate ascospore number, it establishes the direct derivation of the genusDekkeromyces fromDipodascus uninucleatus via the multispored yeast genusKluyveromyces.