[目的]研究用亚硝基胍(NTG)对产可得然胶菌株进行诱变育种及发酵条件优化,为可得然胶产量提升的研究提供参考.[方法]以土壤杆菌HS615(Agrobacterium sp.)为出发菌株,通过NTG诱变筛选高产菌株,再利用单因素和正交试验设计优化发酵培养基,提高得率.[结果]根据致死率确定了NTG的诱变条件为0.5 mg/mL,NTG处理30 min.其次根据菌落颜色和大小确定了初筛平板培养基为1.0%葡萄糖,0.2%酵母粉,0.05%苯胺蓝,初始pH为7.0.经过NTG诱变得到1株可得然胶得率比出发菌株高11.79%的高产菌株.单因素和正交试验设计优化发酵培养基成分为11.0%蔗糖,0.3%玉米浆,0.2%KH2 PO4,0.2%K2 HPO4,0.2%NH4 Cl,0.2%CaCO3,0.1%MgSO4·7H2 O,此时可得然胶得率为5.67%,比优化前提高了6.78%,比初始产量提高了19.37%.[结论]该研究可为可得然胶高产菌株筛选及发酵条件优化提供参考依据.%[Objective]To study the mutagenic breeding and fermentation conditions optimization of the strain producing guar gum by NTG, and to provide reference for the study of the increase of available gum yield.[ Method] The strain was screened by Agrobacterium sp.HS615 ( Agrobacterium sp.) , And the fermentation medium was optimized by single factor and orthogonal design.[ Result] The mutagenic conditions of NTG were determined to be 0.5 mg/mL and NTG for 30 min.Followed by the colony color and size of the screening medium was identified as:1.0% glucose, 0.2% yeast powder, 0.05% aniline blue, the initial pH of 7.0.A strain with high yield of Curdlan was 11.79% higher than that of the original strain.The single factor and orthogonal design optimized fermentation medium components were: 11.0% sucrose, 0.3% corn steep liquor, 0.2% KH2 PO4 , 0.2% K2 HPO4 , 0.2% NH4 Cl, 0.2% CaCO3 , 0.1% MgSO4· 7H2 O at this time Curdlan yield Was 5.67% higher than the pre-optimization of 6.78%, compared with the initial yield increased by 19.37%.[Conclusion] This study can provide a reference for the selection of Curdlan high yield strains and optimization of fermentation conditions.
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