Antarctica is the coldest, windiest, and driest continent on Earth. In this sense, microorganisms that inhabit Antarctica environments have to be adapted to harsh conditions. Fungal strains affiliated with Ascomycota and Basidiomycota phyla have been recovered from terrestrial and marine Antarctic samples. They have been used for the bioprospecting of molecules, such as enzymes. Many reports have shown that these microorganisms produce cold-adapted enzymes at low or mild temperatures, including hydrolases (e.g. α-amylase, cellulase, chitinase, glucosidase, invertase, lipase, pectinase, phytase, protease, subtilase, tannase, and xylanase) and oxidoreductases (laccase and superoxide dismutase). Most of these enzymes are extracellular and their production in the laboratory has been carried out mainly under submerged culture conditions. Several studies showed that the cold-adapted enzymes exhibit a wide range in optimal pH (1.0-9.0) and temperature (10.0-70.0 °C). A myriad of methods have been applied for cold-adapted enzyme purification, resulting in purification factors and yields ranging from 1.70 to 1568.00-fold and 0.60 to 86.20%, respectively. Additionally, some fungal cold-adapted enzymes have been cloned and expressed in host organisms. Considering the enzyme-producing ability of microorganisms and the properties of cold-adapted enzymes, fungi recovered from Antarctic environments could be a prolific genetic resource for biotechnological processes (industrial and environmental) carried out at low or mild temperatures.

Extreme environments such as the Antarctic can lead to the discovery of new microbial taxa, as well as to new microbial-derived natural products. Considering that little is known yet about the diversity and the genetic resources present in these habitats, the main objective of this study was to evaluate the fungal communities from extreme environments collected at Aldmiralty Bay (Antarctica). A total of 891 and 226 isolates was obtained from soil and marine sediment samples, respectively. The most abundant isolates from soil samples were representatives of the genera Leucosporidium, Pseudogymnoascus, and a non-identified Ascomycota NIA6. Metschnikowia sp. was the most abundant taxon from marine samples, followed by isolates from the genera Penicillium and Pseudogymnoascus. Many of the genera were exclusive in marine sediment or terrestrial samples. However, representatives of eight genera were found in both types of samples. Data from non-metric multidimensional scaling showed that each sampling site is unique in their physical-chemical composition and fungal community. Biotechnological potential in relation to enzymatic production at low/moderate temperatures was also investigated. Ligninolytic enzymes were produced by few isolates from root-associated soil. Among the fungi isolated from marine sediments, 16 yeasts and nine fungi showed lipase activity and three yeasts and six filamentous fungi protease activity. The present study permitted increasing our knowledge on the diversity of fungi that inhabit the Antarctic, finding genera that have never been reported in this environment before and discovering putative new species of fungi.

This manuscript makes an impact on the study of micro-organisms from extreme habitats and their possible contribution in discovering new active molecules against pathogens of agricultural interest. Studies on the Antarctic continent and its communities have attracted the scientific community due to the long period of isolation and low levels of disturbance that surrounds the region. Knowing the potential of fungi in this region to produce active secondary metabolites, we aim to contribute to the discovery of compounds with antibacterial action in Xanthomonas citri subsp. citri, a plant pathogen present in several regions around the globe.

O objetivo do trabalho foi utilizar o caldo enzimático dos fungos Aspergillus sp. CBMAI 1198 e Rhizopus sp. CBMAI 1458 isolados de sementes em germinação para degradar a celulose utilizando papel de filtro. Inicialmente os fungos foram cultivados em meio de cultura sólido contendo celulose como indutor de celulases em diferentes valores de pH. A atividade enzimática máxima foi obtida no período de 48 a 72 h após serem cultivados em meio semi-sólido de farelo de trigo (Aspergillus sp. CBMAI 1198: 2,20 e 2,18 UI.mL-1,48-72h, pH 6,0; Rhizopus sp. CBMAI 1458, 5,30 UI.mL-1, pH 6,0, 48 h). Para quantificação da atividade enzimática para celulases totais foi utilizado o método DNS.  Concluiu-se que os fungos Aspergillus sp. CBMAI 1198 e Rhizopus sp. CBMAI 1458 produziram celulases que degradaram a celulose presente no papel de podem ser utilizados na produção dessas enzimas.