Yeast communities associated with bulk-soil, rhizosphere and ectomycorrhizosphere of a Nothofagus pumilio forest in Northwestern Patagonia, Argentina

M. CECILIA MESTRE; CARLOS A. ROSA; SILVANA V.B. SAFAR; DIEGO LIBKIND; SONIA B. FONTENLA

FEMS MICROBIOLOGY ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 p. 531 - 541

0168-6496

Soil microorganisms play an important role in soil quality and they interactclosely with vegetation. Little is known about yeast diversity and function inforest soil ecosystems and their interactions with other biotic soil components,particularly in the mycorrhizosphere. We studied the diversity of yeasts inhabitingthe bulk-soil, rhizosphere and ectomycorrhizosphere of a Nothofaguspumilio forest in Nahuel Huapi National Park (Bariloche, Argentina). Ectomycorrhizalinfection was observed in all N. pumilio trees studied. A total of 126yeast isolates were obtained, including 18 known and three possibly new species.Basidiomycetous yeasts were predominant in all soil fractions, and themost frequently isolated species was Cryptococcus podzolicus. Diversity indicesand multivariate analyses were used to study and compare yeast communitiesin the bulk-soil, rhizosphere and ectomycorrhizosphere. Yeasts able to fermentglucose were found associated with the rhizosphere. Many of the recoveredyeast species were associated with lignocelluloses compound degradation, whichsuggest that yeast plays an important role as a decomposer in these forest soils.Each soil fraction has a distinct yeast assemblage related to their physiologiccapacities and soil nutrient availability.