Budding Morphology of a Psychrophilic Cryptococcus and Related Species Compared with Leucosporidium Scottii

SUMMARY

Cryptococcus bhutanensis, C. himalayensis and C. vishniacii are anamorphic basidiomycotinous yeasts. Cryptococcus bhutanensis and C. vishniacii are the first such reported to lack extracellular urease. The budding characters of these three species occur in an association here described for the first time in yeasts. Budding is monopolar and repetitive through the site of the birth scar. The primary bud is holoblastic, secondary buds enteroblastic and continuous with the inner wall layer of the entire parental cell. Septum formation occurs at or slightly above the level of any previously formed collar (bud scar). The Cryptococcus species, budding monopolarly, have a higher width: length ratio (0.70 to 0.83) than the bipolarly budding Leucosporidium scottii (0.55), in which primary buds are distal to the birth scar. Surface topography reflects the degree of cell encapsulation, but appears to result in part from artifacts of capsule collapse during drying in thinly encapsulated cells.