ABSTRACT
A thermophilic bacterial strain 438 isolated from the Rupi basin, Bulgaria, was chosen as a perspective exopolysaccharide producer It was taxonomically identified as Brevibacillus thermoruber. Among ten different carbon sources tested, maltose in a concentration of 1.8% provided the highest polymer production. (NHJ4)2 HPO4 (0.1%) was chosen as the best nitrogen source. The highest polymer concentration (78.1 mg/l) was synthesized at pH 8.0 and 55°C.