Enhanced gellan gum production by hydrogen peroxide (H2O2) induced oxidative stresses in Sphingomonas paucimobilis

In this study, the effect of H₂O₂-induced oxidative stress on gellan gum production and cell growth were investigated. Gellan gum production was improved and cell growth was inhibited by H₂O₂. A multiple H₂O₂ stresses with different concentrations were developed to optimize gellan gum production. A maximal gellan gum yield (22.52 g/L), which was 35.58 % higher than the control, was observed with 2, 2, 3, 4 mmol/L H₂O₂ added at 6, 12, 18, 24 h, respectively. Moreover, UDP-glucose pyrophosphorylase activity and glucosyltransferase activity were increased with H₂O₂ stresses. This new strategy of multiple H₂O₂-induced oxidative stresses would be further applied to gellan gum production in future study.