AUTHOR=Kim Hye-Jin , Seo Seung-Yeul , Park Heung-Soon , Ko Ji-Young , Choi Si-Sun , Lee Sang Joung , Kim Eung-Soo 

TITLE=Engineered Escherichia coli cell factory for anthranilate over-production

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1081221

DOI=10.3389/fmicb.2023.1081221

ISSN=1664-302X

ABSTRACT=<p>Anthranilate is a key platform chemical in high demand for synthesizing food ingredients, dyes, perfumes, crop protection compounds, pharmaceuticals, and plastics. Microbial-based anthranilate production strategies have been developed to overcome the unstable and expensive supply of anthranilate <italic>via</italic> chemical synthesis from non-renewable resources. Despite the reports of anthranilate biosynthesis in several engineered cells, the anthranilate production yield is still unsatisfactory. This study designed an <italic>Escherichia coli</italic> cell factory and optimized the fed-batch culture process to achieve a high titer of anthranilate production. Using the previously constructed shikimate-overproducing <italic>E. coli</italic> strain, two genes (<italic>aroK</italic> and <italic>aroL</italic>) were complemented, and the <italic>trpD</italic> responsible for transferring the phosphoribosyl group to anthranilate was disrupted to facilitate anthranilate accumulation. The genes with negative effects on anthranilate biosynthesis, including <italic>pheA</italic>, <italic>tyrA</italic>, <italic>pabA</italic>, <italic>ubiC</italic>, <italic>entC</italic>, and <italic>trpR</italic>, were disrupted. In contrast, several shikimate biosynthetic pathway genes, including <italic>aroE</italic> and <italic>tktA</italic>, were overexpressed to maximize glucose uptake and the intermediate flux. The rationally designed anthranilate-overproducing <italic>E. coli</italic> strain grown in an optimized medium produced approximately 4 g/L of anthranilate in 7-L fed-batch fermentation. Overall, rational cell factory design and culture process optimization for microbial-based anthranilate production will play a key role in complementing traditional chemical-based anthranilate production processes.</p>