Redox potential control in anaerobic Clostridium beijerinckii fermentation using single-use vessels

Conference Dates

March 4-8, 2018


Redox potential is an important physiochemical factor which measures the tendency of the medium to acquire electrons. In Clostridium beijerinckii fermentation, redox potential indicates the status of the NAD(P)+ pool regeneration which directs the electron flow leading to solvent production including butanol. In this study, anaerobic C. beijerinckii fermentation was conducted in Eppendorf BioBLU® 3f Single-Use Vessels controlled by the BioFlo® 120 bioprocess control station. The parameters being monitored throughout the fermentation were redox potential and pH using ISM® redox/pH sensors. The objectives of this study were (1) to investigate the effects of redox control on the growth and butanol production of C. beijerinckii; and (2) to validate the suitability of the BioFlo 120 and BioBLU 3f Single-Use Vessel for anaerobic fermentation applications. When C. beijerinckii was grown without redox control, a continuous change of redox potential was observed in the broth. When fermentation ended at 124 h, the optical density at 600 nm (OD600) was 0.8, glucose consumption was 33 % and butanol production was limited. When the redox potential was controlled at -500 mV by redox sensor guided addition of Na2S·9H2O solution, the OD600 was 1.6, glucose consumption was 51 %, and butanol production showed a 2-fold increase. In summary, with the combination of ISM redox sensor and BioBLU Single-Use Vessel, the high variability of redox potential during C. beijerinckii fermentation can be actively controlled to drastically increase biomass growth and solvent production.

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