Antagonistic interaction between bacteria isolated from Antarctic snow

There are relatively few studies on the bacterial communities of the Antarctic snow. Hence, this study was set out to analyze the bacterial communities from snow and to determine whether there is any antagonistic interaction between them. Bacterial strains were isolated from Antarctic snow and were differentiated. Forty six pure cultures were isolated and inhibitory interactions between the bacteria were tested. Initially, non redundant bacterial strains were selected through observation of the colony morphology, bacterial phenotypic characteristics and molecular approach. Of the 46 bacterial isolates, 43 strains were Gram-negative and 3 strains were Gram-positive. Three different shapes were obtained under the microscope. They were single bacilli, diplobacilli and cocci shapes. Molecular characterization was carried out using random amplified polymorphic DNA (RAPD). The RAPD data was analyzed by GelCompar II to construct phylogenetic tree. The phylogenetic relations between the 46 isolates were defined based on cluster of UPGMA. After the RAPD analysis, 10 distinct isolates were chosen for subsequent antagonistic test. All the strains were tested for antagonistic interaction on the R2A solid agar medium. Every single strain was used as 'target strain' once and the other strains were used as the 'tester strain'. All the strains tested did not show inhibitory effects toward each other. This indicates there are no antagonistic interactions between the selected strains. However, one bacteria strain was found exhibit interesting grow feature by performing autolysis when it was cultured on all bacteria strains. Studies would be needed to know more about the bacteria strain and to confirm the hypothesis made