Engineered bacteria cells to help reduce plastic waste

Circular economy

United KingdomSince 2016, bacteria that have been found to breakdown and ingest plastic have been a focus of international research. A team of scientists from the University of Manchester has now produced a biotechnological breakthrough that may allow people to use altered bacteria cells to minimize plastic waste.

PET plastic has long been a source of worry due to the vast volume of plastic produced globally and the environmental impact of non-recycled waste such as drinking bottles, take-away containers, and microplastics.

Plastic’s molecular composition, which is made up of monomers – tiny molecules that are joined together to form polymers – is one of the reasons it is tough to break down. Many investigations have been conducted to far on the ability of bacteria to degrade PET plastic down to its basic monomers. However, there has been little research into these bacteria’s ability to identify and ingest the matching monomers into their cells.

The Manchester Institute of Biotechnology’s new research team investigated the recognition capacity of a critical protein involved in the cellular uptake of the monomer terephthalate (TPA) by the solute binding protein TphC.

Plastic use is anticipated to triple by 2050, and plastic packaging is frequently used only once. Despite increased home and industrial recycling initiatives, there remains a systemic problem as well as an economic potential. Developing microbial plastic breakdown could be critical in addressing this worldwide issue.

The Manchester team used biochemical and structural approaches to figure out how TphC recognizes the substrate TPA. The team used genome mining approaches to discover homologous transporter proteins and enzymes involved in TPA breakdown and assimilation after visualizing the TphC in both open and closed conformations upon TPA binding using techniques that allowed them to visualize the TphC in both open and closed conformations upon TPA binding.

These extracted genomic fragments serve as a genetic resource for future biotechnological and metabolic engineering initiatives aimed at developing circular plastic bio-economy solutions. The use of synthetic enzymes and bacteria to digest and absorb waste plastic is of tremendous interest and potential.

These new discoveries will now aid in the development of modified microbial cells for bio-remediation and bio-based recycling of plastic waste.