干旱区生态环境知识资源中心

Cryptoendolithic microbial communities, living in porous sandstone rocks in the McMurdo Dry Valleys (Ross Desert) of Southern Victoria Land, Antarctica, were found within weathered pegmatite rocks in Northern Victoria Land, and the first endemic Antarctic fungal genus Friedmanniomyces endolithicus anam.- gen. and sp. nov. was isolated from this community. Selected microfungi from these communities and from soil were examined for the production of extracellular enzymes and antibiotic substances. The cryptoendolithic strain CCFEE 5001 was particularly remarkable for consistent glycosidase activity, coupled with barely detectable growth. Chitnase activity was highest in the soil microfungus Verticillium cfr. lecanii (CCFEE 5003). This strain and its purified chitinase were active on Mucor plumbeus, Cladosporium cladosporioides, Aspergillus versicolor, and Penicillium verrucosum, producing mycelial damage and cell lysis. The strain CCFEE 5020, isolated from rocks, showed antibiotic activity against Pseudomonas putida, Sarcina sp., Bacillus subtilis, and Escherichia coli, under the test conditions. Good antibiotic activity was produced in the temperature range of 5 degrees to 25 degrees C, pH 4.0, agitation at 700 rpm, and areation at 1.0 vvm, in media containing 0.5% substrate sugar, though this supported only minimal growth. The investigation of soil microfungi in contrasting sites at the BIOTAS area at Edmonson Point indicated that both the presence of bird colonies and changes in temperature and UV exposure obtained by using plastic cloches influenced species composition and density, A ’Culture Collection of Fungi from Extreme Environments’ (CCFEE) has been established at the University of Tuscia, housing fungal strains from Antarctica.