A novel threat to high technology

[Matterplay1]

If someone engineered a sufficiently robust bacterium or fungus that could break down some common plastics, life could be 'interesting' for a while. For instance, plastic sewer and water mains would be much less durable: perhaps equivalent to high-lignin wood. Not likely to cause the downfall of an entire civilization, but could be extremely inconvenient and expensive. If it happened quickly enough there could be outbreaks of disease due to poor sanitation until all that infrastructure could be replaced. Even the most aggressive plastic-eating 'bug' would still need water, and probably some other nutrients besides the plastic, to really chew into its materials. So in the end it could just be a matter of being a bit less cavalier about exposing plastics to moisture, and treating them more the way we treat wood at present. In the OA future, it's likely quite a few plastic-eating organisms, ranging from microbes and fungi through arthropods and on upwards through arthropods equivalent to termites or to moth larvae will have established themselves in the environment. Good for recycling, perhaps, but it would mean that carbon-based materials that are impervious to decay could be quite rare.