Isolation, identification and hydrolytic enzymes production of aerobic heterotrophic bacteria from two Antarctic islands

The microbial communities in some Antarctic regions still have not extensively investigated. In the present study, we isolated 24 bacterial strains under aerobic conditions from terrestrial samples at two locations in maritime Antarctica: Deception Island and Galindez Island. Phylogenetic analysis based on the 16S rRNA gene sequencing revealed affiliation of the Antarctic isolates to Gammaproteobacteria(54.2%), Betaproteobacteria (8.3%), Firmicutes (20.8%), and Actinobacteria (16.7%). The majority of isolates (92%) are psychrotolerant, and 75% are halotolerant. About 63% of isolated Antarctic bacteria were able to produce hydrolytic enzymes suggesting important role of the strains in carbon and nitrogen cycling in their habitats. Among isolates, producers of proteases (58.3%), ureases (45.8%), polygalacturonases (41.6%), β-glucosidases (33.3%), phytases (20.8%) and ribonucleases (16.6%) were detected. The results revealed higher potential of isolates from Deception Island to produce hydrolytic enzymes than those from Galindez Island. To the best of our knowledge, this is the first report for polygalacturonase production by Antarctic bacteria and β-glucosidase production by culturable Antarctic Burkholderia strain. The results obtained contribute to better understanding of the diversity of culturable heterotrophic bacteria in maritime Antarctica and their potential for production of hydrolytic enzymes allowing detection of promising psychrotolerant producers of industrially important enzymes.