The Application of Multiple Strategies to Enhance Methylparaben Synthesis Using the Engineered Saccharomyces cerevisiae

Methylparaben (MP) is an important member of the paraben family of aromatic compounds, which is under great demand in the industrial market as an antibacterial agent, preservative, and feed additive, and also has potential application value in the preparation of bio-based polyetherester materials. However, the current chemical production method of MP has various problems, such as serious environmental pollution, its dependence on petrochemical resources, and the generation of different types of waste. It is of great significance to develop an environmentally friendly MP synthesis method via synthetic biology. In this work, <i>Saccharomyces cerevisiae</i> was used as the host to construct the biosynthetic pathway of MP and various metabolic engineering strategies were applied to break the bottlenecks in the synthesis process, including the regulation of the rate-limiting steps in the endogenous shikimate pathway, the enhancement of central carbon flux via knocking out competitive pathways and promoting precursors synthesis, and the improvement of the exogenous enzyme expression using promoter engineering. The final engineered <i>S. cerevisiae</i> could produce 68.59 mg/L MP in shake flasks, which was the highest titer of MP synthesized by <i>S. cerevisiae</i> so far. It was indicated that the strategies applied in our work were effective in promoting the synthesis of MP, which not only laid an important foundation for the industrial production of MP, but also provided a platform for the synthesis of other aromatic compounds.