Using metabolic engineering and synthetic biology, the researchers engineered Escherichia coli to oxidize p-xylene—via microbial fermentation—into TPA, a precursor to the ubiquitous bottle resin polyethylene terephthalate.
The route, described in a recent issue of Nature Communications, is a greener alternative to the traditional chemical method for producing TPA from p-xylene. The current industrial process is energy-intensive, requiring high temperature and pressure, and uses heavy metal catalysts. It also produces byproduct 4-carboxybenzaldehyde.
The KAIST process can be carried out at ambient reaction temperature and pressure, does not require heavy metals or other toxic chemicals, and does not produce byproducts.
If reproducible when at industrial scale, the process “will represent a breakthrough in hydrocarbon bioconversions,” according to lead researcher Professor Sang Yup Lee.