science

The catch is that “can eat plastic” and “can solve plastic waste” are very different thresholds.

The bacterium almost completely degraded a PET film in about six weeks at 30C. But that film was extremely favorable material, thin and only about 1.9% crystalline.

https://pmc.ncbi.nlm.nih.gov/articles/10546322/

That's important because a real PET bottle is much harder. PET chains in crystalline regions are packed tightly together, and the enzyme has trouble getting the polymer into its active site. Typical waste PET can have crystallinity above ~25%.

https://doi.org/10.1007/s42452-025-07764-x

Also, P. sakaiensis attacks PET, which is a polyester. It does not give us a general solution for:

• polyethylene (PE) — shopping bags, films, many bottles
• polypropylene (PP) — containers, caps, automotive plastics
• polystyrene (PS)
• PVC
• PTFE
• …

PET happens to contain chemically convenient ester bonds:

PET chain → ester bond → PETase can hydrolyze it

Whereas polyethylene is basically:

–C–C–C–C–C–C–

There's no corresponding easy hydrolysis reaction. That's a much harder biochemical problem.

So if you dumped P. sakaiensis into a landfill, it wouldn't start consuming “the plastic.” It would encounter a giant mixed pile, only some of which is PET, and much of that PET would be physically difficult for it to attack.

Maybe we can engineer something inspired by P. sakaiensis. I don’t think it overcomes the bigger hurdles by itself, though.