Production and characterization of Extracellular Polymeric Substances in Rhizobium with different carbon sources

Abstract

Many microorganisms secrete extracellular polymeric substances (EPS) during their life cycle. Rhizobium is one such bacteria that secrete EPS at suitable conditions. The production of these EPS is also governed by many growth factors and environmental conditions. One such condition is the carbon (sugar) source that is added in the growth medium. For the Rhizobium mannitol is commonly used as the sugar source. But instead sugars like glucose, fructose, sucrose and lactose were also added differently. EPS extracted from the different sugar sources were analyzed. Since the majority of the EPS contains polysaccharides and some amount of proteins, so the samples were tested for the determination of amount of sugars and proteins in various carbon sources. The maximum sugar amount was found in the EPS from mannitol and much protein was derived from the EPS from sucrose. FTIR spectroscopy revealed the presence of functional groups that accounts for its overall structure and functional property. Hence with different carbon sources there will be some variation in the properties of the EPS.