(438l) Quantitative Analysis of Exopolysaccharide Production in a Stirred Tank Bioreactor

Xanthan gum is an extracellular microbial heteropolysaccharide that is produced efficiently by Xanthomonas campestris TISTR 1100 through the fermentation process. This research is to study the effect of agitation rate and temperature on xanthan gum production. A 3.7 litre fermenter with a 2.7 litre of working volume was used throughout this experiment. The ranging of agitation rates from 300 to 700 rpm and the ranging of temperatures from 30 to 35 0C were investigated. Results showed that under the temperature of 33 0C when the agitation rates at 300, 500 and 700 rpm were tested, the maximum viscosity of the fermenter broth were 77.5, 252.5 and 877.5 centripoise. The fermentation kinetics showed the maximum of biomass concentration were 1.04, 2.40 and 2.19 g/L, the maxminum specific growth rate were 0.133, 0.173 and 0.178 h-1, the maximum of xanthan concentration were 0.380, 0.318 and 0.883 g/g/h, the maximum of substrate utilization were 22.29, 26.15 and 23.29 g/L, the maximum of substrate utilization were 11.800, 8.889 and 6.407 g/g/h, respectively. The optimum agitation rate at 700 rpm was chosen as a fixed parameter, while the temperature conditions at 30, 33 and 35 0C were evaluated. Results revealed that the maximum viscosity of fermentation broth were 430, 887.5 and 420 centripoise. The fermentation kinetics indicated that the maximum specific growth rate were 0.224, 0.178 and 0.154 h-1, the maximum specific rate of xanthan production were 0.447, 0.883 and 0.883g/g/h, the maximum specific of substrate utilization were 5.842, 6.407 and 10.913 g/g/h, respectively.