Date of Award
2010
Thesis Type
Masters
Document Type
Dissertation
Divisions
Faculty of Science
Department
Institute of Biological Sciences
Institution
Universiti Malaya
Abstract
In this study, ninety five actinobacterial isolates were cultured from seven soils samples collected on Signy Island, maritime Antarctica. Nine different isolation media were used and the isolates plates were incubated at 15ºC for up to four months. SCN agar serves as the better media for the isolation of actinobacteria. Presence of actinobacteria in the soil samples was also detected using PCR with actinobacteria specific primers. The actinobacterial isolates were characterized based on morphology (Gram-stain, coverslip examination, colour grouping), analysis of DAP isomers, antibacterial activities and by molecular methods (ARDRA, analysis of 16S rRNA sequence and detection of NRPS gene). The isolates were dereplicated using the colour grouping method which resulted in fifteen colour groups ranging from brownish gray, orange, yellow to white. Representatives from the colour groups were selected for DAP analysis: twenty nine isolates contained LL-DAP while seventeen had meso-DAP in their whole cell wall hydrolysates. All ninety five actinobacterial isolates were also dereplicated into sixteen ARDRA groups. Phylogenetic analysis of the 16S rRNA gene sequences from representatives of ARDRA group showed close relationships with the members of the genera Demetria, Glaciibacter, Humicoccus, Kocuria, Marmoricola, Mycobacterium, Nocardia, Rhodococcus, Streptomyces and Tsukamurella. Antimicrobial activity was assayed against six tester bacteria. Forty six actinobacterial isolates inhibited the growth of Staphylococcus aureus, Staphylococcus epididymis and Proteus vulgaris. NRPS genes were detected in seventy nine isolates and most of these isolates showed antibacterial activity. This study shows the presence of novel actinobacteria in maritime Antarctic soils and Antarctic actinobacteria may provide a new source for antibacterial compounds.
Additional Information
Dissertation (M.A.) – Faculty of Science, Universiti Malaya, 2010.
Recommended Citation
Shing Yi, Pan, "Isolation and characterization of actinobacteria from soil samples of Signy Island, Antarctica." (2010). Student Works (2010-2019). 79.
https://knova.um.edu.my/student_works_2010s/79
Creative Commons License
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Included in
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