In this work, a fed-batch fermentation development was performed with recombinant E. coli carrying the PhoA promoter system. The phosphate concentrations tested for this PhoA strain, 2.79 mM to 86.4 mM, were beyond the concentrations previously evaluated for cell growth and product titer. The results from the scouting work was used for design of experiments (DoE) where a range of phosphate levels from 27.1 mM to 86.4 mM was simultaneously evaluated with temperature, pH and DO set points. Definitive screening was used to evaluate these parameters simultaneously and the results indicate that fermentation temperature and phosphate content are the major contributors of product titer. The other factors tested such as pH had a minimal effect and DO had no impact on product titer.

在这项工作中，使用携带PhoA启动子系统的重组大肠杆菌进行了补料分批发酵开发。针对该PhoA菌株测试的磷酸盐浓度为 2.79 mM 至 86.4 mM，超出了之前评估细胞生长和产物滴度的浓度。探索工作的结果用于实验设计 (DoE)，其中同时评估了 27.1 mM 至 86.4 mM 的磷酸盐水平与温度、pH 和 DO 设定点。采用确定性筛选同时评估这些参数，结果表明发酵温度和磷酸盐含量是产品效价的主要影响因素。其他测试因素（例如 pH）影响很小，DO 对产物滴度没有影响。