Nitrogen fixation is the biological process by which atmospheric dinitrogen gas (N₂) is reduced to bioavailable ammonia (NH₃), primarily by prokaryotes possessing the nitrogenase enzyme complex. This ATP-intensive reaction requires strong reducing power and functions only under conditions that protect nitrogenase from irreversible inactivation by oxygen, achieved via specialized cells (heterocysts), microaerobic environments, or respiratory protection. Nitrogen fixation occurs in free-living and symbiotic bacteria and archaea, including rhizobia in legume root nodules, and constitutes a key entry point of inert atmospheric nitrogen into the biosphere, supporting primary productivity and influencing global nitrogen cycling.
Plants need nitrogen to grow. Many legumes meet this need through a symbiotic relationship: They harbor bacteria that fix atmospheric nitrogen and make it available to the plant. Until now, it was largely unclear how a perennial ...
Plants & Animals
Jun 30, 2026
0
11
Securing sustainable food supplies is a key challenge for long-term human exploration and potential habitation of the moon. The moon's soil contains no organic material, and essential plant nitrogen sources like ammonia and ...
Astrobiology
Jun 30, 2026
0
36
Certain plants, including legumes, form specialized root organs known as nodules. These plants establish symbiotic relationships with nitrogen-fixing bacteria and utilize atmospheric nitrogen. This process, termed "root nodule ...
Molecular & Computational biology
Jun 29, 2026
0
4
Agricultural scientists are rethinking their battle plans against plant parasites that cause billions of dollars in annual yield losses for American farmers.
Ecology
Jun 25, 2026
0
8
During the Archean Eon—roughly 4 billion years ago—the Earth was a lifeless planet. The atmosphere lacked oxygen, and there were few, if any, organisms to be found anywhere on the globe. Then something incredible happened. ...
Cell & Microbiology
Jun 12, 2026
0
34
Most major crops, such as wheat and corn, require expensive nitrogen fertilizer to flourish. But what if bacteria could help those plants draw nitrogen from the atmosphere, as peas and beans do?
Biotechnology
May 28, 2026
0
249
Legumes like soybeans, alfalfa, peas, beans, peanuts and many more have a remarkable ability: They can partner with soil bacteria called rhizobia to capture nitrogen from the air in a biological process called nitrogen fixation. ...
Molecular & Computational biology
May 4, 2026
0
7
When lightning strikes a paddock, it does more than scorch grass and scare the cows. The electrical discharge breaks apart nitrogen molecules in the atmosphere, converting them into a form that falls to Earth in rain and ...
Agriculture
Apr 15, 2026
0
27
Climate warming can increase plant growth in permafrost regions by lengthening the growing season, speeding up plant metabolic processes, and allowing deeper root penetration as permafrost thaws. However, the capacity for ...
Plants & Animals
Mar 20, 2026
0
17
Most plants allow fungal microorganisms to enter their root cells and provide them with carbohydrates in exchange for a better supply of nutrients and water. Only leguminous plants like peas, beans, and clover enter into ...
Plants & Animals
Mar 9, 2026
0
29
