Thermophilic Fungi in Biological Soil Crust at the Sevilleta LTER

Biological soil crust are common in arid ecosystems, they are mainly form by the association of a community of microorganisms including fungi, lichens and cyanobacteria. Gypsum deposits are mainly composed of calcium carbonate and contained well developed soil crust communities. The main objective of this study was to characterize thermophilic fungal species isolated from gypsum and other types of crusts.  Crusts were collected at the Sevilleta National Wildlife Refuge in New Mexico. Gypsum samples were plated in malt extract agar and allowed to grow at 50° C for several days. Fungi were isolated to obtain pure cultures and DNA was extracted. Fungi were also incubated at 25°C and 50°C to determine if they were true thermophiles.  Each of the samples kept at 50°C grew between 0.7 and 4.7 cm and samples at room temperature did not show any growth.  DNA extracted from the fungi was amplified using PCR and sequenced using fungal primers in the ITS rDNA region for identification. Three of the samples were identify as Thermomyces and all isolated fungi were true thermophiles. These fungi could represent a source of novel enzymes for industrial purposes.