Optimization of Exopolysaccharides (EPS) production of bacillus cereus

Abstract

The aim of this study was to optimize medium compositions (carbon and nitrogen sources and concentrations) and cultivation conditions (inoculums size and incubation time) for enhancement of exopolysaccharide (EPS) production by Bacillus cereus. The experiments were designed based on conventional method, one factor was varied at a time. Two parameters including crude EPS and EPS concentration were compared among each treatment. Among the investigated factors, carbon source and concentration, incubation time show greater influences on EPS production. A medium composed of maltose with a concentration of 30 g/l, and yeast extract with a concentration of 2 g/L with some other trace elements were found optimized for cell growth and EPS production under the cultivation conditions as inoculum size of 10% and cultivation time of 48h. Under these optimized conditions, the maximum values of crude EPS and EPS concentration were 0.983 ± 0.03 g/L and 0.319 ± 0.019 g/L, respectively. Key words: Exopolysaccharides, Bacillus cereus, optimization