[Medium optimization and fermentation process regulation strategies for enhancing CO₂ conversion to acetic acid by...

To meet the demand for CO₂ resource utilization under the "dual-carbon" goals, the application of medium optimization combined with fermentation process regulation to enhance the acetate production and gas utilization capacity of Acetobacterium woodii represents an effective process optimization strategy. In this study, a multi-strategy approach combining medium optimization and fermentation process regulation was adopted to enhance the acetate yield of an A. woodii SL70 strain obtained via adaptive laboratory evolution (ALE). Firstly, through single-factor experiments and response surface methodology, the optimal culture conditions were determined as follows: gas ratio H₂:CO₂=70:30, NaCl 5 g/L, and yeast extract 4 g/L. Further fermentation process adjustments were performed in a 10 L bioreactor. By increasing the gas flow rate from 1 L/min to 2 L/min and raising the headspace pressure from 1.2 bar to 1.5 bar, the acetate concentration was elevated from 19.18 g/L to 41.87 g/L, representing a 118.3% increase in yield. These modifications also significantly improved the synergy between biomass growth and product synthesis, as well as fermentation stability. This study provides an efficient fermentation medium formulation and process parameters for the industrial application of A. woodii, offering technical support for the directed conversion of CO₂ into high-value acetate products.