携氧剂(H2O2)对野油菜黄单胞菌合成黄原胶的影响

黄原胶(Xanthan Gum)是由野油菜黄单胞菌(Xanthomonas campestris)碳水化合物为主要底物，经发酵产生的‘种酸性胞外杂多糖。发酵中后期黏度增大，氧的传质能力下降，从而影响了黄原胶的产量。本课题研究黄原胶生物合成过程中，H2O2对供氧和提高产胶率的影响。根据添加H2O2实验得出，H2O2添加量为1ml即在发酵液中浓度为4．4mmol／L左右为最适的添加量，最佳添加时刻为48h左右。得出低浓度的H2O2能提高黄原胶的产量，产胶率平均提高了3．28％。

Effects of Oxygen Carrier(H2O2) on the Biosynthesis of Xanthan Gm by Xanthomonas campestris

Xanthan gum is a kind of exospore heteropolysaccharide that can be biosynthesized by Xanthomonas campestris.The yield of Xanthan gum was largely affect by dissolved oxygen in the fermented liquor. As an oxygen carrier, hydrogenperoxide (H2O2) was introduced into fermentation process to improve dissolved oxygen level and increase the yield of Xanthangum. 48h and 4.4mmol/L was the optimal time and H2O2 concentration, respectively. The yield of Xanthan gum was increasedaveragely by 3.28%.