The startup’s genetic switch triggers ammonia production only after microbes colonize a crop’s roots.

Switch Bioworks has developed a genetic switch for soil microbes that triggers ammonia production only when nitrogen levels in the soil drop. The approach addresses a key challenge in microbial fertilizer development: microbes that spend energy on nitrogen fixation often fail to establish healthy colonies around crop roots. The new method lets microbes colonize first and then shift into nitrogen-producing mode.

Synthetic fertilizer production uses the Haber-Bosch process, which relies on natural gas and accounts for roughly 2% of global emissions. The air is nearly 80% nitrogen, but plants cannot use it directly because nitrogen does not react readily. Switch Bioworks aims to replace some synthetic fertilizer with microbes that fix nitrogen naturally, cutting costs for farmers as energy and fertilizer prices have risen.

For agricultural operators, the technology could reduce reliance on chemical fertilizer and lower input costs. The genetic switch design also offers a template for engineering microbes that perform other energy-intensive tasks after establishing a population. Builders of biological systems can apply this two-phase control logic to any microbe that needs to grow first and then produce a valuable compound.

Switch Bioworks is working on several ways to trigger the genetic switch, with the leading option being an automatic response to soil nitrogen levels. The company must prove that its engineered microbes can thrive while fixing nitrogen reliably. If the approach succeeds, farmers could use fewer synthetic fertilizers and reduce costs.

What matters

• Switch Bioworks uses a genetic switch to make soil microbes produce ammonia when nitrogen falls.
• Switch Bioworks’ approach could cut fertilizer costs and emissions for large-scale agricultural operators.
• Watch to see which trigger option Switch Bioworks uses to activate ammonia production.

Why it matters

Watch to see which trigger option Switch Bioworks uses to activate ammonia production.

This GenAI News article was prepared in original wording using reporting and materials published by MIT Technology Review AI. Source reference: https://www.technologyreview.com/2026/09/01/1143195/microbe-fertilizer-switch-bioworks/.

Drafted by the GenAI News review pipeline.