一株产高黏度耐酸性黄原胶生产菌的选育及其发酵工艺研究

摘要

选用黄原胶生产菌株野油菜黄单胞杆菌XG30-18,经微波辐射后再经亚硝基胍（NTG）处理筛选出一株产高黏度耐酸性黄原胶的突变菌株MW-42-NTG-6,并对其发酵条件进行初步筛选。确定其培养基以蔗糖和玉米淀粉做为混合碳源、大豆分离蛋白为氮源。通过正交试验确定最适发酵条件为接种量8%、转速240r/min、pH7.0、培养温度28℃。在此发酵条件下,产胶率最高可达到3.92%、黏度为1790cP、耐酸性测定1%黄原胶溶液pH值为4.2。%Xanthomonas campestris XG30-18 was radiated by microwave and then treated with nitrosoguanidine（NTG） and a mutant strain named as MW-42-NTG-6 was obtained.The strain had the ability to produce high-viscosity and acid-resistant xanthan gum.The optimal carbon and nitrogen sources for the strain were sucrose ＋ corn starch and soybean protein isolate,respectively.The optimal fermentation conditions for production of high-viscosity and acid-resistant xanthan gum by the strain,as determined using orthogonal array design method,were inoculum amount of 8%,fermentation pH of 7.0,rotation speed of 240 r/min and fermentation temperature of 28 ℃.Under these conditions,the viscosity,yield,acid-resistant pH of xanthan gum were 1790 cP,3.92% and 4.2,respectively.