Production of xanthan gum from Xanthomonas campestris for food industry

Xanthan gum is a polysaccharide that primary structure is composed of glucose, mannose, glucoronate, acetyl group and pyruvyl group. The aqueous solution of xanthan gum exibits a high viscosity colloid. It is widely used as a stabilizer, or a thickening or an emulsifying agent for many application such as oil recovery in petrochemical industry, paper, adheseives, ceramic, pharmaceutical, cosmetics, leather and food industry. Xanthan gum can be synthesized by chemical method and by microorganism. For this research it was produced by Xanthomonas campestris TISTR 1100 through fermentation process. Then factors influenced growth rate and productivity e.g. the shaking speed, the initial concentration of inoculum and the initial concentration of glucose in fermentation medium at 30 deg C were studied. The experiments carried out on a rotary shaker by using 1, 5, 10, 15 and 20 percent of initial inoculum concentration at 200, 300 and 400 rpm were tested. The result showed that 15 percent of initial inoculum at 200 rpm gave the maximum viscosity of fermentation broth 355 centipoise (cP), the maximum xanthan gum 6.35 g/l and the maximum biomass 5.64 g/l. At 300 rpm the result showed that 15 percent of initial inoculum gave the maximum viscosity of fermentation broth 495 cP, the maximum xanthan gum 8.91 g/l and the maximum biomass 7.49 g/l. While the result at 400 rpm showed the maximum viscosity of fermentation broth not higher than 28 cP, the maximum xanthan gum not higher than 0.5 g/l and the maximum biomass not higher than 2.3 g/l for every initial inoculum concentration used. Then the initial concentrations of glucose in fermentation medium at 10, 15, 20, 25 and 30 g/l were experimented with 15 percent of initial inoculum at 200 and 300 rpm. It was found that 20 g/l of initial glucose at 200 rpm gave the maximum viscosity of fermentation broth 357.5 cP, the maximum xanthan gum 6.34 g/l and the maximum biomass 5.29 g/l while 25 g/l of initial glucose at 300 rpm give the maximum viscosity of fermentation broth 490 cP, the maximum xanthan gum 8.80 g/l and the maximum biomass 7.38 g/l respectively.