Succinoglycan production by Agrobacterium tumefaciens

Abstract

A strain of Agrobacterium tumefaciens isolated from soil was cultivated under various conditions in shake flasks to study exopolysaccharides (EPS) production. NMR analysis revealed that the EPS obtained was a succinoglycan-like polymer. Optimal yields of EPS were obtained using sucrose and lysine as the carbon and nitrogen sources, respectively. Supplementation of the medium with various chemicals resulted in a more or less marked effect on the polymer yield and properties: in particular, high phosphate levels and non-ionic surfactants led to the production of polymers of different molecular sizes in yields up to 13.7 g/l. Oxygen availability also affected the polymer yield and quality. The chemical structure was substantially unaffected by the various fermentation conditions tested. A fermentation carried out in a laboratory-scale fermentor yielded 9.6 g/l succinoglycan from 15 g/l sucrose in the basic medium without further supplements.