气升式反应器中高山被孢霉发酵生产花生四烯酸过程的动态温度控制研究

在利用高山被孢霉发酵生产花生四烯酸(Arachidonic Acid,ARA)过程中,考察了不同规模和培养环境下,单一以及动态温度控制对菌体生长和ARA合成的影响。结果表明:相对于机械搅拌罐,利用气升式反应器发酵生产ARA具有明显优势。同时,较高温度(25℃)有利于高山被孢霉菌体生长,而较低温度(16℃)有利于ARA合成。在此基础上进行动态控温发酵,即起始发酵温度25℃,72h后以每12h下降1.5℃至16℃,然后保持16℃至发酵结束。采用此控制策略,ARA产量达到4.7g/L,与单一温度(25℃)控制相比提高了38.2%。 

Study on improved arachidonic acid production by Mortierella alpina with dynamic temperature-control in airlift bioreactor

Constant and dynamic temperature-control was inverstigated for efficient arachidonic acid (ARA) production by Mortierella alpine in different fermentation scales and environments. The results showed that airlift bioreactor was more suitable for ARA production process compared with mechanical stirring fermentor.Meanwhile, cell growth rate showed to be optimum at 25℃, while ARA ratio in lipid showed to be maximal at16℃. As a result, a dynamic temperature-control strategy, in which the culture temperature was controlled at25℃ at the first 72 h and linearly decreased 1.5℃ for every 12 h till 16℃, then kept at 16℃ for the rest of the fermentation, was developed in the airlift bioreactor. With this control strategy, the ARA production level reached4.7g/L which was increased 38.2% compared with the level of constant temperature (25℃) control strategy.