膜生物反应器连续发酵法制取甲醇及其发酵动力学初探

Preliminary studies on kinetics model of continuous fermentation of methanol with membrane bioreactor

采用膜生物反应器系统连续发酵制取甲醇能够及时分离产物,有效抑制甲醇对细胞的毒副作用,因此延长稳定期产甲醇的时间以提高产量。本文对比间歇发酵,研究了不同稀释率0.05h^(-1)～0.13h^(-1)下连续发酵的甲醇生成和甲烷氧化菌株Methylomonas.QJ16生长状况,并且初步探讨了该菌株的生长、甲醇形成的动力学特性。结果表明,稀释率为0.1h^(-1)时,菌体积累和甲醇的体积产率均较高,最长连续发酵持续时间为300h左右;描述连续发酵过程的动力学模型,菌体生长和产物合成的曲线拟合优度分别为0.991、0.994,基本反映了该甲烷氧化菌株连续发酵过程的动力学特征。

A membrane bioreactor system was applied in the fermentation of methanol. In this system, methanol was separated by micro-pore membrane according to the size and the toxicity of methanol to bacteria was well controlled. The production of methanol in the fermentation bioreactor was accretion. The yield of methanol and the growth of Methylomon QJ16 were investigated at different dilution rates ranging from 0.05h^-1 to 0.13 h^-1 on the basis of the batch fermentation. It was seen that methanol concentration and the productivity could be maintained over 300 h at the dilution rate of 0. 1h^-1. A simple model was proposed for growth and methanol substance production. The fit values of the three models were 0. 991 and 0. 994, respectively. The model could provide a reasonable description for each parameter during the growth phase. The result showed that it was an effective process to produce methanol in a membrane bioreaetor system.