Diversity and ecology of cultivable fungi isolated from the thermal soil gradients in Deception Island, Antarctica.

ABSTRACT

We surveyed the diversity of cultivable fungi isolated from cold and hot volcanic soils of Deception Island, Antarctica. Seventy-four fungal isolates were identified; these belonged to 17 taxa in the genera Aspergillus, Penicillium, Pseudogymnoascus, Purpureocillium, and Mortierella. The fungal assemblages showed low diversity, richness, and dominance indices. The Aspergillus taxa were dominant in the soils at 0 °C, 50 °C, and 100 °C. Aspergillus lacticoffeatus, Aspergillus cf. ruber, Penicillium citrinun, and Purpureocillium sodanum were present only in soils having a temperature of 100 °C. Aspergillus calidoustus was present in all thermal soils and displayed the highest densities. The majority of fungi displayed mesophilic behavior; however, different isolates of Aspergillus lacticoffeatus and Aspergillus niger were able to grow at 50 °C; these are phylogenetically close to the causative agents of aspergillosis in immunocompromised individuals. Deception Island perhaps represents one of the most visited regions in Antarctica and the tourism there has increased over the last 20 years, especially by elderly tourists, probably with weak immune systems, come in contact with the resident microorganisms, including the thermo-resistant opportunistic Aspergillus species.