New expression system to increase the yield of phloroglucinol

Phloroglucinol (PG) is an important chemical that has been produced in engineered E. coli. Low yield and high cost are the bottlenecks that limit the industrialisation and popularisation of PG biosynthesis. In this study, a new expression system (pNEW vector) was developed for PG biosynthesis by using inexpensive p-isopropylbenzoate (cumate) as the inducer, and the copy number control element (rop) was added to optimise the original pNEW vector, which not only promoted the PG yield, but also reduced the leakage expression. Compared to traditional IPTG inducible expression system, 2-fold enhancement of PG yield was obtained with optimised expression system and the cost of inducer was reduced to 1/9. These results provide technical support for the biosynthesis of PG and reference for the selection of induced expression systems for other chemical biosynthesis.