Nitrogen-fixing microbes

Microbes that convert nitrogen gas from the air into ammonia that plants can use as fertiliser.

• Air is 78% nitrogen, but its strong triple bond makes it unusable to plants; only the microbial enzyme nitrogenase can break it biologically.
• Legumes such as soybeans host fixing bacteria in root nodules; cereals such as corn and wheat lack that partnership.
• Synthetic fertiliser, made from natural gas by the Haber-Bosch process, uses about 1–2% of world energy; Pivot Bio edits soil microbes to feed corn.
• Edited microbes supply only part of a crop's needs, and results vary with soil, weather and practice, so field evidence is key.