In July, 2021, Science, one of the most prestigious journals in science, dedicated an issue to the ecological threat of plastics. In industrialized societies, avoiding plastics is nearly impossible. From our clothing to our kitchenware and homes, tons of plastics surround us.
Plastic waste, including microplastics from our laundries, now pollute the soil and the waters of the planet. Organisms have had just a brief exposure to plastics, and they remain novel to their physiology. These can have devastating impacts on organisms, including alterations in embryonic development, fertility, weight gain, and diseases.
We have already found some microbes that can combat the problem. However, they work slowly and not on all plastics.
https://science.sciencemag.org/content/373/6550/36
Despite the rush to find plastic-eating bacteria, one needs to remember that these new abilities could have unknown side effects. For example, they could break down the wastes into other hazardous products. Also, natural plastic-eating bacteria are already working on the problem, albeit slowly. One of these is in the genus Pseudomonas which contains many pathogens. That particular Pseudomonas appears to attack polyurethane.
https://www.ecowatch.com/scientists-find-bacteria-that-eats-plastic-2645582039.html
Should plastic-eating bacteria become common, a potential problem would be their spread to places we don’t want them–like our plumbing, equipment, and clothing. Plus, bacteria can mutate to use related compounds.
Although a work of fiction, The book Ill Wind by Kevin J. Anderson and Doug Beason warns about mutations in an oil-eating bacterium. Great piece of sci-fi and a cautionary tale.