title: Dioszegia antarctica sp. nov. and Dioszegia cryoxerica sp. nov., psychrophilic basidiomycetous yeasts from polar desert soils in Antarctica.
abstract: During a survey of the culturable soil fungal population in samples collected in Taylor Valley, South Victoria Land, Antarctica, 13 basidiomycetous yeast strains with orange-coloured colonies were isolated. Phylogenetic analyses of internal transcribed spacer (ITS) and partial LSU rRNA gene sequences showed that the strains belong to the Dioszegia clade of the Tremellales (Tremellomycetes, Agaricomycotina), but did not correspond to any of the hitherto recognized species. Two novel species, Dioszegia antarctica sp. nov. (type strain ANT-03-116(T) =CBS 10920(T) =PYCC 5970(T)) and Dioszegia cryoxerica sp. nov. (type strain ANT-03-071(T) =CBS 10919(T) =PYCC 5967(T)), are described to accommodate ten and three of these strains, respectively. Analysis of ITS sequences demonstrated intrastrain sequence heterogeneity in D. cryoxerica. The latter species is also notable for producing true hyphae with clamp connections and haustoria. However, no sexual structures were observed. The two novel species can be considered obligate psychrophiles, since they failed to grow above 20 degrees C and grew best between 10 and 15 degrees C.
authors: School of Marine Sciences, University of Maine, 5735 Hitchner Hall, Orono, ME 04469, USA.
authors: Laurie B
authors: LB
authors: Connell
authors: Adaptive Symbiotic Technologies, Seattle, WA 98125, USA.|College of Forest Resources, University of Washington, Seattle, WA 98195, USA.
authors: Regina
authors: R
authors: Redman
authors: Department of Biology, University of Washington, Seattle, WA 98195, USA.|US Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA.
authors: Russel
authors: R
authors: Rodriguez
authors: School of Marine Sciences, University of Maine, 5735 Hitchner Hall, Orono, ME 04469, USA.
authors: Anne
authors: A
authors: Barrett
authors: School of Marine Sciences, University of Maine, 5735 Hitchner Hall, Orono, ME 04469, USA.
authors: Melissa
authors: M
authors: Iszard
authors: Centro de Recursos Microbiológicos (CREM), Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors: Álvaro
authors: Á
authors: Fonseca
mesh_terms: D000864:Antarctic Regions; D001487:Basidiomycota / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D017931:DNA Primers; D003889:Desert Climate; D006601:Hexoses / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology
chemical_list: D017931:DNA Primers; D006601:Hexoses