氧化还原电位调控混合糖为底物的丁醇发酵

控制丁醇发酵过程中的氧化还原电位（oxidoreduction potential， ORP）能够大幅提高丁醇产量和果糖利用率，并降低终点有机酸浓度。实验考察了以葡萄糖和果糖混合糖为底物，通过泵入无菌空气控制ORP分别不低于-490、-460、-430及-400 mV丁醇发酵情况。其中，控制ORP不低于-460 mV时，丁醇和总溶剂产量分别达到13.19 g·L^-1及19.71 g·L^-1，相对于不控制ORP的丁醇自然发酵分别提高了139.38%及117.07%，残糖浓度降低至3.20 g·L^-1，糖利用率高达94.18%。该调控策略有效地解决了以葡萄糖和果糖混合糖为底物的丁醇发酵过程中存在的残糖浓度高、丁醇产量低的问题。

Batch butanol fermentation using mixed sugars of glucose and fructose with oxidoreduction potential control

Butanol production and sugar utilization were greatly improved via oxidoreduction potential (ORP) control strategy during batch acetone-butanol-ethanol (ABE) fermentation with less acids accumulation. Batch fermentations using mixed sugars of glucose and fructose were conducted by pumping sterile air into the fermentor to control ORP above-490,-460,-430 and-400 mV, respectively. When ORP was controlled above-460 mV, butanol production and total solvents reached 13.19 g·L^-1 and 19.71 g·L^-1, respectively, increased by 139.38% and 117.07% compared to the uncontrolled process. At the end of fermentation, residual sugars concentration dropped to 3.2 g·L^-1 and sugar utilization was as high as 94.18%. The results showed that the ORP-control strategy significantly improved sugar utilization, especially for fructose, and butanol production from mixed sugars, indicating that ORP-control could show a stimulatory effect on ABE fermentation and would be an economically competitive strategy for improving fermentation efficiency.