(532c) Upcycling Waste Polyethylene Terephthalate and Other Plastics into High-Value Bioproducts Using Novel Synthetic Biology Tools

Polyethylene terephthalate (PET), a polyester with a high ratio of aromatic components, is one of the most abundant plastics with its global annual production reaching almost 70 million tons. The accumulation of recalcitrant PET in the environment has led to the current global plastic pollution crisis. Currently, hydrolysis has been commonly utilized to depolymerize PET into monomers terephthalic acid (TPA) and ethylene glycol (EG), and these monomers can be repolymerized into virgin PET for further processing without any value added. To realize the valorization of PET waste, synthetic biology can be applied.

Our previous study has identified a non-pathogenic bacterium Rhodococcus jostii PET (RPET) that can directly utilize TPA and EG from alkaline hydrolysis of PET as the sole carbon source [1, 2]. Despite its robust capability to catabolize a wide range of aromatic compounds and accumulate diverse storage compounds, few genetic tools have been identified in R. jostii. To overcome this limitation, we have developed and characterized a series of genetic tools to control gene expression, construct genetic circuits, and integrate large heterologous pathways into the genome of RPET. These genetic tools have been utilized to improve the productivity of either lipids or lycopene in RPET using TPA and EG from alkaline hydrolysis of PET as the sole carbon source. Our results demonstrate that those genetic tools can facilitate our efforts to valorize waste PET and other plastics into sustainable biochemicals. In this presentation, we will discuss our recent progress toward upcycling mixed plastic waste as sole carbon sources into value-added bioproducts [3].

[1] TS Moon et al. U.S. Provisional Patent Application

[2] J Diao, Y Hu, Y Tian, R Carr and TS Moon. Upcycling of poly(ethylene terephthalate) to produce high-value bioproducts. Cell Reports. 42, 111908 (2023)

[3] To be submitted soon