ISOLATION AND CHARACTERIZATION OF A THERMOPHILIC BACTERIUM, GEOBACILLUS SP. STRAIN MAS2, FROM A HOT SPRING OF BALOCHISTAN, PAKISTAN
Till to date, there is no report on isolation of microorganisms from the Mahiwal hot water spring in Balochistan, Pakistan. In the current manuscript, we report on isolation and morphological, biochemical and molecular characterization of a thermophilic microorganism from this hot water spring. The isolated bacterial strain, MAS2, is rod shaped with 1 µm width and 5 µm length. It forms cream-colored slimy colonies. The strain has the ability to grow in the presence of air between 40 and 75 °C with an optimum growth temperature and pH of 65 °C and 6.5, respectively. It can utilize various sugars, hydrocarbons and carboxylic acids as sole carbon source. No additional salt is required for its growth, though relatively higher yield was achieved with the addition of 0.5% NaCl. The strain MAS2 is capable of producing several important extracellular enzymes of industrial use including an amylase, a lipase, an oxidase and a protease. The 16S rRNA gene sequence of strain MAS2 exhibited high homology with various species belonging to genus Geobacillus. The highest homology of 98.66% was observed with Geobacillus kaustophilus. However, the biochemical characteristics of the strain were more similar to Geobacillus thermopakistaniensis and Geobacillus uzenensis. These results indicate that strain MAS2 represents an unidentified species belonging to genus Geobacillus. Keywords: Thermophiles; 16S rRNA sequence: Geobacillus sp. MAS2; biochemical characterization; extracellular enzymes.