Abstract
The nutritional requirements of Agrobacterium tumefaciens in production of extracellular polysaccharides (EPS) were studied in a chemically defined medium containing 10% centrifuged date molasses as a sole carbon source. The maximum EPS yield was obtained at pH 7, in presence of 7 g/L, KNO3, with 5% of 12 hour old inocula and incubated statically in Kole flaks at 30 degrees C. As in secondary metabolite production, EPS production started late in the exponential phase and the maximum yield was obtained at the stationary phase. Among the inducers tested, succinic acid proved to be the best for the yield of EPS. The rheological properties of polymer solutions were also studied. Viscosity was not affected by pH and temperature. The pure polysaccharide was not toxic and the polymer solution showed a good emulsifying activity.