Microbes convert Styrofoam into plastic

Bacteria could help transform a key component of disposable cups, plates and utensils into a useful eco-friendly plastic, significantly reducing the environmental impact of this ubiquitous, but difficult-to-recycle waste stream.

The microbes, a special strain of the soil bacterium Pseudomonas putida, converted polystyrene foam — commonly known as Styrofoam — into a biodegradable plastic, according to Kevin O’Connor, Ph.D., of University College Dublin. O’Connor’s study is among the first to investigate the possibility of converting a petroleum-based plastic waste into a reusable biodegradable form.

O’Connor and his colleagues from Ireland and Germany, utilised pyrolysis, a process that transforms materials by heating them in the absence of oxygen, to convert polystyrene — the key component of many disposable products — into styrene oil. The researchers then supplied this oil to P. putida, a bacterium that can feed on styrene, which converted the oil into a biodegradable plastic known as PHA (polyhydroxyalkanoates). The process might also be used to convert other types of discarded plastics into PHA, according to O’Connor.