(28e) Biosynthesis of Styrene and 4-Hydroxystyrene By Exploiting Aromatic Amino Acid Exporter and Biosensors in Escherichia coli

Microbial bioproduction of aromatic compounds is of great research interest since it serves as a more sustainable approach compared to the traditional petroleum-based production. In this study, we established a microbial co-culture platform for bioproduction of styrene and 4-hydroxystyrene, from aromatic amino acid phenylalanine and tyrosine, respectively. To this end, metabolite biosensor-assisted cell population selection system was first established for over-production of phenylalanine and tyrosine. Subsequently, an aromatic acid exporter was utilized for reducing the intracellular accumulation and improving the biosensor-based cell selection efficiency. E. coli strains producing styrene and 4-hydroxystyrene from amino acid precursors were constructed and co-cultivated with the amino acid over-producers to establish the co-culture systems for de novo biosynthesis. Notably, the use the exporter facilitated the mass transfer of the amino acids between the co-culture strains and thus improved the bioproduction performance. Our results showed that the biosynthesis of styrene and 4-hydroxystyrene was achieved with high efficiency, indicating strong potentials of this novel approach.