Reclassification of the Cryptococcus humicola complex

Abstract

Ten strains of the Cryptococcus humicola complex were reclassified on the basis of sequence analyses of 18S rDNA and internal transcribed spacer regions and DNA-DNA reassociation experiments. They were differentiated into seven species including C humicola. Five novel species are proposed: Cryptococcus daszewskae sp. nov. (type strain CBS 5123T = JCM 11166T = MUCL 30649T), Cryptococcus fragicola sp. nov. (type strain JCM 1530TT = CBS 88981), Cryptococcus longus sp. nov. (type strain CBS 5920T = JCM 11167T = MUCL 30690T), Cryptococcus musci sp. nov. (type strain JCM 1531T = CBS 8899T) and Cryptococcus pseudolongus sp. nov. (type strain JCM 9712T = CBS 8297T). A syntype of Sporobolomyces albidus JCM 1460T is also revealed to be a distinct species; the name Cryptococcus ramirezgomezianus nom. nov. is therefore proposed for Sporobolomyces albidus Ramírez Gómez (type strain IJFM 502T = CBS 2839T = JCM 1460T = NRRL Y-2478T), since the name Cryptococcus albidus (Saito) C. E. Skinner has already been recognized for a distinct species within the genus Cryptococcus. Strains possessing either Q-9 or Q-10 have been reported to occur in C. humicola; however, after reclassification, the ubiquinone type of the species in each phylogenetic group was shown to be uniform, indicating that it is a useful criterion for the taxonomy of the Trichosporonales.