Anthranilate, an intermediate of the shikimate pathway, is a high-value aromatic compound widely used as a precursor in the production of dyes, fragrances, plastics and pharmaceuticals. Traditional strategies adopted for microbial anthranilate production rely on the implementation of auxotrophic strains—which requires aromatic amino acids or complex additives to be supplemented in the culture medium, negatively impacting production costs. In this work, we engineered the soil bacterium Pseudomonas putida for high-titer, glucose-dependent anthranilate production by repurposing elements of the Esa quorum sensing (QS) system of Pantoea stewartii. The P_esaS promoter mediated a self-regulated transcriptional response that effectively knocked-down the expression of the trpDC genes. Next, we harnessed the synthetic QS elements to engineer a growth-to-anthranilate production switch. The resulting plasmid-free P. putida strain produced the target compound at 3.8 ± 0.3 mM in shaken-flask cultures after 72 h—a titer >2-fold higher than anthranilate levels reported thus far. Our results highlight the value of dynamic flux regulation for the production of intermediate metabolites within highly-regulated routes (such as the shikimate pathway), thereby circumventing the need of expensive additives.

邻氨基苯甲酸是莽草酸途径的中间体，是一种高价值的芳香族化合物，广泛用作染料、香料、塑料和药品生产的前体。用于微生物邻氨基苯甲酸酯生产的传统策略依赖于营养缺陷型菌株的实施——这需要在培养基中补充芳香族氨基酸或复杂的添加剂，从而对生产成本产生负面影响。在这项工作中，我们通过重新利用Pantoea Stewartii的 Esa 群体感应 (QS) 系统的元素，设计了土壤细菌恶臭假单胞菌以生产高滴度的葡萄糖依赖性邻氨基苯甲酸盐。P _esaS启动子介导了一种自我调节的转录反应，有效地抑制了trpDC基因的表达。接下来，我们利用合成的 QS 元素来设计一个生长到邻氨基苯甲酸生产的开关。得到的无质粒P。恶臭菌株在 72 小时后在摇瓶培养物中产生了 3.8 ± 0.3 mM 的目标化合物——比目前报道的邻氨基苯甲酸盐水平高出 2 倍以上。我们的研究结果强调了动态通量调节对于在高度调节的途径（如莽草酸途径）中产生中间代谢物的价值，从而避免了对昂贵添加剂的需求。