系统研究了表面活性剂种类(Tween-40、Tween-60、Tween-80、曲通-X-100(Triton X-100)、十二烷基硫酸钠(SDS)、十六烷基三甲基溴化胺(CTAB))、表面活性剂添加浓度以及表面活性剂添加时间对大肠杆菌BW25113生长和发酵产L-鸟氨酸的影响。研究结果表明,发酵0h添加浓度范围为0.1g/L 2g/L的表面活性剂时,Tween-40、Tween-60、Tween-80、Triton X-100和SDS对大肠杆菌BW25113的生长和L-鸟氨酸的产量均无影响,而CTAB对L-鸟氨酸生物合成有一定的促进作用。CTAB的作用效果因CTAB的添加浓度和添加时间的不同而有所差异。发酵8h添加与0.1g/L为CTAB最适添加时间和最佳添加浓度。在该条件下,添加CTAB对大肠杆菌BW25113发酵产L-鸟氨酸的促进作用最大,L-鸟氨酸产量可达743mg/L并且几乎不影响大肠杆菌BW25113的生长。与不添加CTAB的对照组相比,L-鸟氨酸产量提高1.25倍,发酵周期也缩短10h。
The effects of different kinds of surfactants(Tween-40,Tween-60,Tween-80,Triton X-100,sodium dodecyl sulfate(SDS) and cetyl trimethyl ammonium bromide(CTAB)),concentration of the surfactant and additive time of the surfactant on cell growth and L-ornithine production by E.coli BW25113 were investigated systematically.When adding 0.1g/L2g/L the surfactantat 0h culture,CTAB could promoted the production of L-ornithine,in contrast,Tween-40,Tween-60,Tween-80,Triton X-100 and SDS were not found to show any effect during the fermentation courses.Effects of CTAB on the fermentation of L-ornithine depended on the concentration of CTAB and the additive time of CTAB.The optimum additive time and CTAB concentration were 8h and 0.1g/L.Under the optimal conditions as above,CTAB did not influence the growth of E.coli BW25113;the final yield of L-ornithine could be improved to the highest level and accumulated at 743mg/L,which is 1.25 times higher than that of control.At the same time,the period of fermentation was shortened about 10h.