New research has uncovered the secret side-gig of a 3.2 billion-year-old class of enzymes, called nitrogenase.
Scientists long believed that the primary function of these enzymes was to convert nitrogen into ammonia, an essential process that makes Earth habitable. But the new research describes a use for this enzyme that could help create more eco-friendly plastic production.
The enzymes are present in large quantities in a type of soil-dwelling bacteria, called Rhodospirillum rubrum. When exposed to oxygen-depleted environments, which nitrogenase thrives in, these bacteria reveal a previously unknown biological pathway, allowing it to transform sulfur into ethylene.
Ethylene is a natural gas used in the production of everyday plastics, like disposable grocery bags.
Together, the new observations may offer a safer way to create plastics without fossil fuels. They could also help farmers better understand how an abundance of ethylene may be harming their crops.
“We thought, well, that’s weird.”
Organisms burping out ethylene is something scientists have been actively studying for some time, but Justin North, a research scientist at Ohio State and first author of the new study, says that these previously identified biological pathways to ethylene had a bit of an explosive problem.
“For about a decade, researchers have studied the biological production of ethylene through a different mechanism that occurs in oxygenated environments,” North tells Inverse. “There is a technical hurdle to scaling up that process as ethylene and oxygen mixed at industrial scales could be explosive.”
Because this newly discovered pathway in bacteria is anaerobic, meaning it doesn’t require oxygen, North says it may be possible to scale something like this without the risk of explosions.
The study was published Thursday in the journal Science.