Biodegradable PET alternative produced at “unprecedented” levels, study shows

A research team at Kobe University, Japan, has developed E. coli bacteria to produce pyridinedicarboxylate (PDCA), a monomer for biodegradable plastics and an alternative to PET. The scientists have produced the compound from glucose at “unprecedented levels” and without byproducts.

PDCA is biodegradable. Materials incorporating it show physical properties comparable to or even surpassing those of PET, which is commonly used in packaging and textiles.

The findings, published in Metabolic Engineering, show that the researchers have achieved the production of PDCA in bioreactors at concentrations more than seven-fold higher than previously reported.

Kobe University bioengineer Tanaka Tsutomu says: “Most biomass-based production strategies focus on molecules consisting of carbon, oxygen, and hydrogen. However, there are highly promising compounds for high-performance plastics that include other elements such as nitrogen, but there are no efficient bioproduction strategies. And purely chemical reactions inevitably generate unwanted byproducts.”

“Our group approached the challenge from a new angle. We aimed to harness cellular metabolism to assimilate nitrogen and build the compound from start to finish.”

Bioproduction strategy

Unlike earlier pathways, in which nitrogen incorporation occurs via nonbiological or chemically driven mechanisms, the findings highlight the potential of enzyme-catalyzed nitrogen assimilation as a more efficient and biologically sustainable strategy.

“The significance of our work lies in demonstrating that metabolic reactions can be used to incorporate nitrogen without producing unwanted byproducts, thereby enabling the clean and efficient synthesis of the target compound,” says Tanaka.

“The ability to obtain sufficient quantities in bioreactors lays the groundwork for the next steps toward practical implementation.”

“More generally, though, our achievement in incorporating enzymes from nitrogen metabolism broadens the spectrum of molecules accessible through microbial synthesis, thus enhancing the potential of bio-manufacturing even further.”

The researchers say that future strategies, including dynamic CvpobA expression and precise tuning of pyruvate kinase activity, could further improve PDCA’s scalability and industrial viability.