Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
680332 | Bioresource Technology | 2015 | 7 Pages |
Abstract
In this study, a three-stage oxidoreduction potential (ORP) control strategy was developed to improve propionic acid (PA) production using engineered Propionibacterium jensenii ATCC 4868 (pZGX04-gldA) in a 3-L bioreactor. Specifically, ORP was controlled at â200Â mV from 0 to 36Â h, â300Â mV from 36 to 156Â h, and â400Â mV after 156Â h. The PA titer increased from 21.38 to 27.31Â g/L. The effects of ORP regulation on key intracellular metabolites were studied, demonstrating that ORP can both regulate NADH/NAD+ ratio and the activities of some enzymes involved in electron transport and redistribute metabolic flux. We integrated the ORP control strategy with a fed-batch culture method and increased PA production to 39.53Â g/L. This new ORP control strategy may be useful in the optimization of other anaerobic processes.
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Authors
Xin Zhuge, Jianghua Li, Hyun-dong Shin, Long Liu, Guocheng Du, Jian Chen,