Influence of culture conditions on exopolysaccharide production by Lactobacillus rhamnosus strain C83

The influence of culture conditions on growth and exopolysaccharide (EPS) production by Lactobacillus rhamnosus strain C83 was investigated using fermentor batch cultures. A temperature shift (from 37 to 25 °C) at the beginning of the exponential growth phase (0–5 h) enhanced EPS production. Furthermore, an optimal environmental pH of 6·2–7·2 improved the performance of strain C83 and partially anaerobic culture conditions (pO2 from 0 to 10%) triggered EPS over‐production by the cells. The sugar composition of this polymer was independent of culture conditions, such as carbon source, medium composition, temperature, pH, pO2 and growth phases. In all cases, galactose and glucose were the principal components.