RELATIONSHIPS WITHIN THE BLACK YEAST GENUS EXOPHIALA BASED ON ITS1 SEQUENCES

Relations between type isolates of recognized species and synonymous n ames in the black yeast genus Exophiala and some similar taxa were ana lysed on the basis of their ribosomal internal transcribed spacer regi on 1 (ITS1) DNA sequences. Synonymy of Mycotorula schawii with E. derm atitidis, and of Hormodendrum negronii with E. jeanselmei var. lecanii -corni were confirmed. The synonymy of E. salmonis and E. brunnea was not confirmed. Sporotrichum gougerotii and Torula bergeri proved to be identical but in contrast to earlier reports this taxon differs from E. castellanii. Exophiala castellanii, E. angulospora, E. moniliae, E. dopicola, E. brunnea and E. alcalophila were recognized as separate s pecies. Several clusters of closely related species were found, among which were E. pisciphila, E. psychrophila and E. salmonis on the one h and and E. dermatitidis, E. jeanselmei var. heteromorpha, Sarcinomyces phaeomuriformis and Pullularia prototropha on the other. Nadsoniella nigra and its var. hesuelica were found to be identical. They clustere d with Phaeococcomyces elegans, Sporotrichum gougerotii and Torula ber geri. A further cluster comprised E. jeanselmei var. jeanselmei, P. ex ophialae and E. spinifera. The varieties of E. jeanselmei were found t o be unrelated and should therefore be maintained as separate species. In general, the phylogenetic relationships established in this study did not conflict with those found in sequencing studies of small and l arge subunit RNA genes.