强化伍氏醋酸杆菌转化CO2产乙酸的培养基优化与发酵调控策略

Medium optimization and fermentation process regulation strategies for enhancing CO2 conversion to acetic acid by Acetobacterium woodii

摘要:

为了契合“双碳”目标下的CO₂资源化利用需求，采用培养基优化与发酵工艺调控提高伍氏醋酸杆菌(Acetobacterium woodii)乙酸产量和气体利用能力，是一种有效的工艺优化策略。本研究对实验室适应性进化(adaptive laboratory evolution, ALE)得到的A. woodii SL70菌株进行培养基优化及发酵工艺调控提高其产乙酸能力。首先，通过单因素实验和响应面优化的方法，确定了最佳培养条件为气体比例H₂:CO₂=70:30，NaCl 5 g/L，酵母浸粉4 g/L。进一步在10 L生物反应器中进行发酵工艺调控，将通气量由1 L/min提高至2 L/min，罐压由1.2 bar提升至1.5 bar，使乙酸含量从19.18 g/L提升至41.87 g/L (产量提升118.3%)，且生物量与产物合成的协同性及发酵稳定性显著改善。本研究为A. woodii的工业化应用提供了高效菌株的发酵培养基配方及发酵工艺参数，为CO₂定向转化为高附加值乙酸盐类产品提供了技术支撑。

Abstract:

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.