Characterization of two new thermoacidophilic microalgae: Genome organization and comparison withGaldieria sulphuraria

Thermoacidophilic algae (Cyanidiaceae) constitute a taxonomic group with interesting phylogenetic and ecological implications. In this report, we have classified three thermoacidophilic microalgal isolates from Rio Tinto (Spain) using a combination of classical analysis of phenotypic features and the characterization of their electrophoretically determined karyotypes by means of pulsed-field gel electrophoresis. Using this technique, we have been able to demonstrate that thermoacidophilic algae genomes have the smallest genomes of all photosynthetic eukaryotes studied so far. In addition, we show that two of these Rio Tinto isolates may constitute new species within the genus Galdieria.