Characterization of Halophilic Bacteria Isolated from Khewra Salt Mines

Abstract

Halophilic bacteria can populate every niche of earth. These halophiles have a great potential of exopolysaccharides production that is of considerable importance in various industries. To screen EPS producing halophiles, saline soil samples were collected from Khewra salt mines, Jehlum, Pakistan. Twenty-two morphologically different bacterial strains were isolated by serial dilution method. All strains were considered as moderate halophilic bacteria as they could grow at 3-15% of NaCl concentration whereas only three strains could grow at 15% of NaCl, which belonged to the genus Bacillus and Pseudomonas. For screening of EPS production, P-medium was used. While for the estimation of slime production, congo-red agar was used that exhibited positive results by appearance of black colored colonies by many strains. Moreover, EPS production was analyzed quantitatively and qualitatively. Isolated Staphylococcus and Bacillus species produced high amount of EPS (20g/L). “Moderate halophiles” play an important role in therapeutics, bioremediation, food and medicine, petroleum and tanning industries by producing EPS. Recently, growth of many agriculture crops has been improved by using beneficial halophiles in saline soils. Consequently, with the help of these beneficial halophiles we can give benefit to mankind