Exploration of extremophilic microorganisms for production and applications of exopolysaccharides

Extremophilic microorganisms live in extreme environmental conditions such as high or low temperature, high or low pH, high concentration of salt and accordingly are classified as thermophilic, psychrophilic, alkaliphilic, acidophilic and halophilic respectively. They adapt themselves to the extreme conditions by producing novel biomolecules like heat shock proteins, cold active enzymes, compatible solutes and exopolysaccharides. Extremophilic microorganisms maintain their cellular integrity with the help of exopolysaccharide (EPS) which constitutes slime or a hydrated matrix that keeps the cells embedded. EPS are composed of carbohydrates and some amino acids. Thermophilic microorganisms namely Thermus, Geobacillus, Bacillus, Thermococcus and halophilic microorganisms namely Halomonas, Halobacillus, Haloferax and Halococcus are reported and well-studied for production of EPS. The EPSs exhibit emulsifying, viscofying and antioxidant properties that find applications in food industry, oil recovery and anticancer agents.