Promoter engineering has been employed as a strategy to enhance and optimize the production of bio-products. Availability of promoters with predictable activities is needed for downstream application. However, whether promoter activity remains the same in different gene contexts remains unknown. Six consecutive promoters that have previously been determined to have different activity levels were used to construct six different versions of plasmid backbone pTH1227, followed by inserted genes encoding two polymer-producing enzymes. In some cases, promoter activity in the presence of inserted genes did not correspond to the reported activity levels in a previous study. After removing the inserted genes, the activity of these promoters returned to their previously reported level. These changes were further confirmed to occur at the transcriptional level. Polymer production using our newly constructed plasmids showed polymer accumulation levels corresponding to the promoter activity reported in our study. Our study demonstrated the importance of re-assessing promoter activity levels with regard to gene context, which could influence promoter activity, leading to different outcomes in downstream applications.

启动子工程已被用作增强和优化生物产品生产的策略。下游应用需要具有可预测活性的启动子的可用性。然而，在不同的基因环境中启动子活性是否保持不变仍然未知。先前已确定具有不同活性水平的六个连续启动子用于构建六个不同版本的质粒骨架 pTH1227，然后插入编码两种聚合物产生酶的基因。在某些情况下，存在插入基因的启动子活性与先前研究中报告的活性水平不对应。去除插入的基因后，这些启动子的活性恢复到之前报道的水平。这些变化被进一步证实发生在转录水平。使用我们新构建的质粒的聚合物生产显示出与我们研究中报告的启动子活性相对应的聚合物积累水平。我们的研究证明了重新评估与基因背景相关的启动子活性水平的重要性，这可能会影响启动子的活性，从而导致下游应用的不同结果。