ABSTRACT
One of the mechanisms of microbial cells to protect them from outer environment is production of extracellular polysaccharides also called as exopolysaccharides (EPS). EPS are high molecular weight, carbohydrate-containing biopolymers produced by certain microorganisms exterior to the cell surface as capsule or loosely associated as slime. EPs are found to be of two types, viz. homopolysaccharides which contain only one type of monosaccharide and heteropolysaccharides that contain more than one. In case of microbial EPS, mostly rheological properties like viscosity, gel formation and stability are studied. EPS play many important roles and functions based upon their structure and composition. Halophiles are the salt loving microorganisms that thrive in hypersaline environments originated mostly by evaporation of seawater. The structure, composition and yield of EPS vary with the microbial strains and the fermentation conditions. Microorganisms differ in critical factors like carbon and nitrogen sources, temperature, pH and requirement of minerals.
