Bioprospecting for extracellular enzymes from culturable Actinobacteria from the South Shetland Islands, Antarctica

The development of novel biological products, such as enzymes, dyes, antibiotics, and others with high potential use for biotechnological applications, continues to stimulate the search for microorganisms in extreme environments. In recent years, the study of Antarctic ecosystems and their microorganisms has received more attention because psychrophilic microorganisms—mainly bacteria and their enzymes—have assumed considerable importance for biotechnological applications. In this study, we characterized a collection of 30 culturable Actinobacteria isolated from the South Shetland Islands, Antarctica, in order to relate their distribution and ability to produce extracellular enzymes with their biotechnological potential. The isolates belonged to eight genus in the phylum Actinobacteria: Arthrobacter, Brevibacterium, Curtobacterium, Janibacter, Knoellia, Rhodococcus, Streptomyces and Thermoleophilum. The screening for biologically active products showed that all the evaluated strains produced at least one extracellular enzyme at 4 °C, with protease, gelatinase and cellulase enzymes being the most common. In conclusion, our data showed that various Antarctic ecosystems are good sources for isolating cultivable Actinobacteria. Furthermore, these bacteria provide high-quality biological material for screening cold-active enzymes that have potential biotechnological applications and economic benefits.