Exo-Polysaccharides and his role symbiotic relationship between Rhizobium and leguminous plants: A review article

Abstract

Exo-Polysaccharides is a compound of an extracellular acid nature with high molecular weights, an exo-cellular product of an acid nature with high molecular weights that accumulate on the surface of the cell and secrete to the cell's circumference, Its main function is to protect the cell from environmental pressures as well as its important role in the association of link  bacterium with the roots of legumes plants and then in the formation of the root nodules during the symbiotic relationship that results in the stabilization of atmospheric nitrogen to ammonia.

Exopolysaccaride (EPS) can be classified as polysaccharides depending on the type of units that make up the polysaccharide. Correlation and size of component units and degree of polymerization it is called Homopolysaccharides or Heteropolysaccharide and the type of Exo-Polysaccharides produced varies between types of the Rhizobium bacterium, the type of sugars, the method of association and the size of the constituent units and the degree of their composition. The production of Exopolysaccaride is influenced by various factors, including the composition of the media environment and the culture conditions , which have been of great importance in the growth of microbiology and stimulate their production of Exo-Polysaccharides and provide them with the energy necessary for biological processes. One of the most important factors affecting the production of the bacterial strain ,the components of the dietary medium and  pH.