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

## TL;DR

Scientists engineered yeast to produce methylparaben, a chemical used in industry, using a more eco-friendly method.

## Contribution

This is the first report of methylparaben biosynthesis using engineered yeast with optimized metabolic pathways.

## Key findings

- Engineered yeast produced 68.59 mg/L of methylparaben in shake flasks.
- Metabolic engineering strategies improved carbon flux and enzyme expression for efficient synthesis.
- The method provides a foundation for producing methylparaben and other aromatic compounds sustainably.

## Abstract

Methylparaben (MP) is an important member of the paraben family of aromatic com-pounds. Herein, S. cerevisiae was selected as the chassis to achieve MP biosynthesis. The carbon flux of the targeted biosynthesis pathway was enhanced by modulating the central carbon metabolism pathways (shikimate pathway, glycolysis pathway, pentose phosphate pathway). A suitable promoter combination strategy was screened out to improve the expression of heterologous enzymes. Combined with the optimization of the fermentation process, MP was successfully produced by the engineered S. cerevisiae. This is the first report on MP biosynthesis using yeast and lays the foundation for further research on the bio-production of MP, as well as other parabens.

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, Saccharomyces cerevisiae 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 S. cerevisiae could produce 68.59 mg/L MP in shake flasks, which was the highest titer of MP synthesized by S. cerevisiae 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.