Scientists are engineering bacteria that can provide nitrogen, an essential ingredient for plant growth, to wheat crops. Credit: Shakeel Ahmed/Anadolu Agency/Getty

The world’s farms depend on synthetic nitrogen fertilizers to increase crop yields, but the production and use of these chemicals generates billions of tonnes of greenhouse-gas emissions every year. Now, scientists are making progress on a greener alternative: bioengineered bacteria.

This approach takes a cue from natural bacteria that ‘fix’ nitrogen into a useful form and provide it to certain plants. Scientists are engineering genetic features into bacteria with the aim of enabling them to fix nitrogen for important food crops, such as maize (corn) and wheat, that don’t have such natural microbial partners.

In a comment published on 10 November in Nature Biotechnology 1 , researchers suggest that bioengineered bacteria could eventually replace up to half of synthetic fertilizers .…