Dimorphic behaviour and taxonomy of Trichosporiella sporotrichoides.

Three strains of Trichosporiella sporotrichoides van Oorschot showed divergent reactions to suspension plating. A comparison was made with other yeast-like fungi and some descriptive terms were redefined or introduced. Strain CBS 671.74 developed the same hyphae with lateral conidia as in streak cultures. Strain CBS 577.77 showed initial-stage budding eventually giving rise to hyphae with lateral conidia. CBS 152.76 showed phenotypic segregation with suspension plating and an additional pseudomycelial form in liquid culture. Further differences between the strains were found in carbohydrate composition of cells, ultrastructure of cell walls and in growth patterns on various sugars. Two strains with basidiomycetous affinities are reclassified in the genus Trichosporon. A third strain with ascomycetous affinities is redescribed as Trichosporiella ornithopoda spec. nov.