Image of the geothermal site at Pisciarelli (Napoli, Italy). Acidic sulphur fumes rise from a fissure in the rocks. The bright green biomat is populated by a diverse assemblage of eukaryotic thermoacidophiles, the Cyanidiales. The Cyanidiales is a primitive order of single-celled red algae. Pisciarelli, located centrally in the Phlegrean Fields near Napoli, is one of the many extreme habitats in which Cyanidiales thrive. The pH is highly acidic (0-2) and the temperature varies from 50-55°C. We have used environmental PCR to identify the different species and strains that co-exist in this environment. We are also studying Cyanidiales from other extreme habitats such as cells that grow within rocks (cryptoendolithic) and are covered by an amorphous layer of silica. Many of these taxa are novel and phylogenetically divergent. These results indicate the existence of undiscovered biodiversity of Cyanidiales. The novel taxa are being isolated, cultured, and studied with TEM and other microscopic and physiological methods.

Images of the geothermal site of Pisciarelli (Napoli, Italy). Sulphur steams rise from fissures in the rocks. The yellow mineral distributed throughout the photo is sulphur deposits from the active fumaroles. Other minerals present in this amazing environment include heavy metals such as arsenic and lead.

Image of an acid pool at the geothermal site of Pisciarelli (Napoli, Italy). The water temperature varies from 60-80°C and has a pH from 0-2.