Microbes that can help degrade polyurethane

Researchers from the German Helmholtz Centre for Environmental Research-UFZ in Leipzig have identified a strain of bacteria capable of degrading some of the chemical building blocks of polyurethane plastic.

Polyurethane is a lightweight, flexible, and insulating type of petroleum-based plastic. It is used in everything from refrigerators and buildings, to footwear and furniture. The material is difficult and energy-intensive to recycle and destroy, which means most of the waste ends up in landfills where it releases a number of toxic chemicals, some even carcinogenic.

The use of bacteria and fungi to break down oil-based plastics is an ongoing area of research (for examples, click here and here).

The team in Germany is one of the first to focus on the biodegradation of polyurethane plastics. The researchers used a bacterium known as Pseudomonas putida, which is capable of ingesting toxic organic compounds as its sole source carbon, nitrogen, and energy. The project aims to identify the genes that code for the extracellular enzymes that are capable of breaking down certain chemical compounds in polyester-based polyurethanes. Extracellular enzymes, also called exoenzymes, are proteins secreted outside of a cell that cause a biochemical reaction.

However, there is no immediate plan to engineer these or other enzymes using synthetic biology techniques for bioplastic production. That could involve, for instance, genetically converting the bacteria into mini-factories capable of transforming oil-based chemical compounds into biodegradable ones for planet-friendly plastics.

Photo: Keith Weller / USDA