【摘要】 以枯草芽孢杆菌HSD060为出发菌株,注入不同剂量N⁺离子束,定向筛选磺胺胍抗性（SG^r）或阿拉伯糖利用缺陷株（ara^-）单突变株,复筛得到产量提高显著的单突变株B13（SG^r）和B67（ara^-）,肌苷的摇瓶发酵产量分别比出发菌株提高16.3%和20%。注入剂量为3×10¹⁵ions/cm²时,SG^r突变率较高:1×10¹⁶ions/cm²时,ara^-突变率较高;且发生SG^r突变的频率高于ara^-突变。再次以最适剂量分别对B13、B67菌株进行离子束诱变,筛选SG^r和ara双突变菌株,经复筛得到产量显著提高的双突变株B13-105、B13-5和B67-1,平均肌苷发酵产量比相应的单突变株分别提高23.5%、20.4%和23.1%。更多还原

【Abstract】 Different N⁺ ion doses were implanted into an inosine-producing strain Bacillus subtilis HSD060 for the screening of anti-sulfaguanidine（SG^r） and arabinose utilization deficiency（ara） mutants.Two single mutants, B13（SG^r） and B67（ara^-）,were obtained and their inosine yields in shake flask were increased by 16.3%and 20%, compared with the original strain.The comparatively higher mutation rate of SG^r mutants occurred at implantation dose of 3×10¹⁵ ions/cm²,while that of ara^- mutants at 1×10¹⁶ ions/cm².Strains B13 and B67 were treated with the optimum N⁺ ion dose once again for the screening of double mutated strains with SG^r and ara^-.Mutants B 13-105,B 13-5 and B67-1 were obtained with double mutations,the inosine yields of which in shake flask were increased by 23.5%,20.4%and 23.1%,respectively,compared with their parent strains.更多还原