Antibacterial and antioxidant potential of polar microorganisms isolated from Antarctic lichen Psoroma sp.

Abstract

Recent studies suggest that bacterial communities in lichens contribute structurally and ecologically, but their biological activities are not fully investigated. In this study, we explored biological potential of microorganisms that are isolated from Antarctic lichen Psoroma sp. Using their bacterial cell culture extracts, we evaluated antibacterial and antioxidant properties. Among 20 bacterial species that were isolated from Antarctic lichen Psoroma sp., PAMC 26508 (Streptomyces sp., similarity: 100%) showed antibacterial activities against all target bacteria with inhibition zone diameter of 7 to 9. PAMC 26537 (Burkholderia sordidicola, similarity: 98.828%) exhibited higher antioxidant potential with an inhibition rate of 60.12% in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 58.69% in 2,2'-azino-bis[3-ethyl benzothiazoline-6-sulphonic acid] (ABTS) assay than control ascorbic acid (29.31%). Our results indicated that they have potential to be used as novel source of antibacterial and antioxidant agents. Key words: Antarctica, antibacterial/antioxidant, lichen associated bacteria, lichen, Psoroma sp.