There are many many bacterial enzymes known to be able to able to break down plastics such as PET etc. But one bottleneck has been low/slow catalytic activity,

There are many many bacterial enzymes known to be able to able to break down plastics such as PET etc. But one bottleneck has been low/slow catalytic activity, so it sounds like they passed that hurdle which is impressive! However, a non-insignificant practical challenge is that enzymes are often very picky about what physical environment they work the best in. The pH has to be just right, as well as the temperature and even having enough metal ions present (often needed for the enzymes catalytic site). Looks like they engineered it to work at higher temps, which is another feat. There are also challenges in scaling up recombinant enzyme production: making sure the enzyme's activity isn't affected by post-translational modifications (such as glycosylations) in the host organisms the gene will be expressed by, and making sure the enzyme maintains it's catalytic activity after it's been purified and concentrated.