Sporulation in Candida Pulcherrima, Candida Reukaufii and Chlamydozyma Species: Their Relationships with Metschnikowia

Abstract

Sporulation of Candida pulcherrima, C. reukaufii, Chlamydozyma pulchcrrima, Chl. reukaufii and Chi. zygota was achieved. Ascospores are acicular and 2 per ascus, characteristic of the genus Metschnikowia. On the basis of 2 distinct ascus shapes, 2 new species are described, M. pulchcrrima and M. reukaufii. Zygote formation occurs after mixing haploid cultures derived from M. zobellii and the above Candida and Chlamydozyma species. Taxonomic implications are considered, and Chlamydozyma is concluded to be an illegitimate name. The complete life cycles of these yeasts are presented. Germinating ascospores give rise to heterothallic haploid cultures, which on mating form zygotes, then diploid vegetative cells, and chlamydospores. Chlamy- dospores may differentiate to form asci, or revert to vegetative cells by budding. Details are given of the methods with which sporulation was induced. Reduced temperatures and diluted media provide optimum conditions for this process. Medium composition and pH are of lesser importance. Ecologically, Metschnikowia is shown to be a much more widely distributed genus than has been believed hitherto.