Utilization of Low Molecular Weight Lignin-Related Aromatic Compounds for the Selective Isolation of Yeasts: Rhodotorula vanillica, a New Basidiomycetous Yeast Species

Abstract

Summary Low molecular weight lignin-related aromatic compounds were used as sole sources of carbon and energy for the selective isolation of yeasts. A total of 227 yeast strains were isolated from terrestrial and aquatic habitats and ascribed to three groups: ascomycetous yeasts (17.6%), ascomycetous yeast-like microorganisms (5.3%) and basidiomycetous yeasts (77.1%). About half of the strains, representing the proportions of the various groups, were identified to the species level. Among the basidiomycetous yeasts, those affiliated to the Ustilaginales were present in higher number (75 strains) than the representatives of the Tremellales/Filobasidiales (16 strains). The ability of each identified isolate to grow in liquid medium with the same composition as the solid selective isolation medium was checked. Only 41% of the ascomycetous yeasts were able to grow, whereas all the ascomycetous yeast-like isolates and 90% of the basidiomycetous yeasts had that capacity. A novel basidiomycetous anamorphic yeast species was found among the strains collected and is described as Rhodotorula vanillica . Conspecificity with the phenotypically similar species Rhodotorula ingeniosa was excluded based on absence of DNA-DNA complementarity.