Plastics are not forever: Bacteria are evolving to eat them

Plastics are not forever: Bacteria are evolving to eat them. By Joanne Nova.

Plastics are made from oil, and like other hydrocarbons there is a lot of energy locked up in their chemical bonds. Wherever there is energy, specialist lifeforms evolve to consume that energy. Our plastics have opened up a new ecological niche, and bacteria are rushing in to fill it. Soon no plastics will be able to evade their hunger for long.

Plastics are a free dinner for life on Earth, so it was just a matter of time before microbes evolved to eat it.

A PET bottle normally takes 16 – 48 years to break down, but if it were lunch for microflora it would take weeks instead. Hydrocarbons are ultimately just different forms of C-H-O waiting to be liberated as carbon dioxide and water. The only question was “how long” it would take bacteria and fungi to break those unusual bonds.

Sooner or later all plastic will be biodegradable.

The first bacteria known to chew through PET bottles was discovered at a Japanese rubbish dump in 2016.

But we had no idea then just how advanced the microbial world of plastic processing was. A new study shows. Instead of hunting for single bacteria Zrimec et al mined through collected metagenomes of soil and ocean and found not just 5 or 10 new enzymes but 30,000. It appears that they could metabolize at least ten different types of plastic.

And in places where there was more plastic pollution, there were more enzymes. All over the world a whole new ecosystem is rising out of the puddles and bubbles and grains of sand. Enzymes that degrade plastics are found all over the world. …

The plastics “crisis” is a crisis of not understanding:

The new 250 page “Consensus” Study (their words) by the National Academies of Science, Engineering and Medicine, is as out of date and useless as it sounds. While it is scoring headlines, scaring us about accumulating plastics, it largely writes off the idea that microbes will evolve to degrade plastic, saying “measurable biodegradation (complete carbon utilization by microbes) in the environment has not been observed.” Which is one of those true but useless statements.

The bottom line: We don’t want to drown dolphins and trap turtles, but we shouldn’t demonize plastics either. Don’t throw rubbish in the ocean or toss hype in national news. It’s all litter.

This follows on from our post last week, The ocean plastic crisis is a fantasy.

Give us back our plastic bags and straws. They cause less waste and energy use than their replacements.