Sporidiobolus longiusculus sp. nov. and Sporobolomyces patagonicus sp. nov., two new yeasts of the Sporidiobolales isolated from aquatic environments in Patagonia, Argentina. Libkind et al.

Submitted to IJSEM

saved 19.08.04

During a survey of carotenogenic yeasts carried out in northwestern Patagonia (Argentina), several ballistoconidia-producing strains belonging to the order Sporidiobolales were isolated from aquatic environments. Five strains were found to represent two novel species, for which the names Sporidiobolus longiusculus (type strain CBS 9654^T = PYCC 5818^T = CRUB 1044^T) and Sporobolomyces patagonicus (type strain CBS 9657^T = PYCC 5817^T = CRUB 1038^T) are proposed. The particular micromorphological feature of Sporidiobolus longiusculus are the elongated basidia, which are 5 to 6 times longer that those of the remaining species of the genus Sporidiobolus. Based on the sequences of the D1/D2 domains of the 26S rDNA, the most closely related species to Sporidiobolus longiusculus is Sporobolomyces bannaensis, whereas Sporobolomyces marcillae is the closest relative of Sporobolomyces patagonicus. Complete internal transcribed spacer (ITS) sequence analysis confirmed the separated position of Sporidiobolus longiusculus whereas for Sporobolomyces patagonicus no nucleotide differences were found towards Sporidiobolus pararoseus CBS 491^T. Negative mating experiments between strains of Sporobolomyces patagonicus and strains of Sporidiobolus pararoseus and low DNA-DNA reassociation values for the type strains of the two species validated the proposal of Sporobolomyces patagonicus as a distinct species. Information on additional Patagonian Sporobolomyces isolates is also included in this report.