表面活性剂对天然红色素发酵的影响

探讨了表面活性剂的添加对天然红色素灵菌红素发酵的影响,并在此基础上对发酵培养基进行优化,达到提高色素产量的目的。以发酵液中灵菌红素的OD535为指标,通过对单因素实验和正交实验进行分析,优化培养基条件。结果表明:在吐温-80、十二烷基磺酸钠和二甲亚砜3种表面活性剂中,添加二甲亚砜的效果最佳,其最佳添加浓度为0.1 g/L,最佳添加时间为发酵44 h,产量与对照组相比提高近1倍;通过正交实验进一步优化发酵培养基,发现在发酵培养基中添加二甲亚砜0.1 g/L、脯氨酸0.1 g/L、甘氨酸1 g/L、组氨酸0.5 g/L,灵菌红素产量为对照组的2.38倍,优化效果最佳。因此,在灵菌红素发酵中后期添加适量的表面活性剂有助于灵菌红素产量的提高。

Effect of Surfactants on Production of Prodigiosins by S.marcescens

Prodigiosin is a secondary metabolite produced by some Serratia sp,actinomycetes,and a few other bacteria.Prodigiosin has several biological activities such as immunosuppressive activity,antibacterial,antimycotic,antimalarial activities,etc.To enhance the productivity of prodigiosins,the effect of surfactants and precursors in culture medium were investigated.In the research,one-factor experimental design and the orthogonal tests were applied to optimize the composition of culture medium.The results showed that the best surfactant was DMSO compared with Tween-80 and SDS.The relative optimized condition of DMSO was 0.1 g/L at 44 h.The productivity of prodigiosins was twice as much as the control experiment.The orthogonal experiment indicated that the best condition was DMSO 0.1 g/L,praline 0.1 g/L,glycine 1g/L,and histidine 0.5 g/L.Adding the nutrients according to the optimization condition into the original culture medium,the productivity of prodigiosins was 1.38 times higher than the control.The test showed that it was feasible to promote the productivity of prodigiosins by adding the surfactants in the later stage of fermentation.