高产辅酶Q10类球红细菌的化学诱变筛选及其发酵培养基优化

利用菌株对（维生素K3+叠氮化钠+对羟基苯甲酸）的复合抗性作为筛选标记，对产辅酶Q10的类球红细菌（Rhodobacter sphaeroides）使用亚硝基胍进行化学诱变，筛选高产菌株并采用响应面法优化其发酵培养基。结果表明，经诱变选育得到一株遗传稳定的辅酶Q10高产菌株R.sp3-7，其最佳发酵培养基组成为：葡萄糖31.7 g/L，玉米浆干粉5.6 g/L，（NH4）2SO4 5.3 g/L、谷氨酸钠 3.0 g/L、NaCl 3.0 g/L、MgSO4·7H2O 12.5 g/L、KH2PO4 3.0 g/L、CaCO3 2.0 g/L、辅液1 mL/L。在此培养条件下，诱变菌株R.sp3-7的辅酶Q10产量达（93.63±0.59） mg/L，与出发菌株相比提高了116.8%。 关键词：中图分类号：TS201.3 文章编号：0254-5071（20１6）06-0090-06 doi:

Screening of high CoQ10-producing Rhodobacter sphaeroides by chemical mutagenesis and its fermentation medium optimization

Using multiple resistance of vitamin K3, NaN3 and p-hydroxybenzoie acid(PHBA) as selective marker, CoQ10-producing Rhodobacter sphaeroides was mutated by nitrosoguanidine (NTG), and the high CoQ10-producing strains was screened. The fermentation medium was optimized by response surface methodology. Results showed that a strain R.sp3-7 with genetic stability and high CoQ10-production was obtained by mutation breeding. The optimum component of fermentation medium was glucose 31.7 g/L, corn steep powder 5.6 g/L, (NH4)2SO4 5.3 g/L, sodium glutamate 3.0 g/L, NaCl 3.0 g/L, MgSO4·7H2O 12.5 g/L, KH2PO4 3.0 g/L, CaCO3 2.0 g/L and auxiliary fluids 1 ml/L. Under the conditions, the yield of CoQ10 produced by mutant strain R.sp3-7 was up to (93.63±0.59) mg/L, which was increased by 116.8% than that produced by original strain.