Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: June 3, 1999
Publication Date: N/A
Technical Abstract: Nearly 500 species of teleomorphic and anamorphic ascomycetous yeasts are currently recognized. Genetic isolation of these species has been determined from their divergence in the variable 600-nucleotide domains D1/D2 of 26S rDNA, and for many, from comparisons of nuclear DNA reassociation. Twelve new ascomycetous species were detected among unidentified isolates maintained in the ARS Culture Collection (NRRL) through comparisons with a database of 26S D1/D2 sequences for all currently recognized yeasts. The new species are placed in the genera Pichia (3), Saccharomycopsis (1) and Candida (8), and have been characterized from molecular, genetic, and phenotypic properties. The Pichia species are heterothallic, whereas the Saccharomycopsis species is homothallic. Relationships with currently recognized species have been determined from phylogenetic analyses of D1/D2 sequences. This work suggests that large numbers of new yeasts will be discovered when molecular comparisons are routinely used for strain characterization.