Genomes from Limits of Life

NIZOVOY P; BELLORA N; LIBKIND D; MOLINÉ M

San Carlos de Bariloche

Simposio; 34 International Specialized Symposium on Yeasts; 2018

ISSY- ARgentina

For long time extremophiles were terra incognita, since aggressive conditions of their ecological niches were considered as dead zones. Nowadays it is well known that these places are inhabited by a wide spectrum of microorganisms that became valuable resources in biotechnology and interesting candidates when exploring life origin. Odd microorganisms cannot be studied by comparing their genomes with model organisms (like Saccharomyces cerevisiae or Cryptococcus neoformans). Generating a good quality database of extreme life genomes is thus essential. In this work we sequenced yeast isolated from extremely acidic, and high heavy metal polluted environments. Selection of strains was based on their outstanding metal and acid tolerance. Source origin was either anthropogenic (acid rock drainage from São Domingos mine in Portugal) or natural (argentinian acidic water bodies from Río Agrio-Lago Caviahuesystem -RALC-). Three portuguese strains were selected along with phylogenetically related strain exclusively found in RALC. These four Goffeauzyma strains (G. iberica,G. metallitolerans, G. aciditolerans and G. agrionensis), collectively known as ARDecoclade resulted in genomes ranging from 16 to 25 mbp with comparable number of putative genes predicted (mean 6.2k). Four strains belonging to an undescribed speciesthat may represent the first report of an acidophilic yeast, were also sequenced (twoPortuguese strains and two RALCs). Assemblies resulted in 20.3 mbp average,accounting for 7k number of putative genes. Coniochaeta fodinicola and Rhodotorulamucilaginosa, more ubiquitous strains but frequently found in these two extreme environments, were sequenced and their genomes analyzed for gene prediction. Genomes quality was assessed for all ten basidiomycetous strains by comparing traditional genomic statistics and genome completeness was tested by looking for setsof eukaryotic core genes. Automatic and manually curated sets of annotations are being generated in order to explore possible genomic traits of their extreme tolerance, whether it was shaped in a natural or anthropogenic environment.