Nitrogen fixing organisms

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Researchers at Stanford have developed methods of increasing bio-available nitrogen in the soil. Nitrogen is the major limiting nutrient on industrially farmed land. Even though the atmosphere is 78% nitrogen, it is in a form that makes it inert and inaccessible to plants. Thus, nitrogen needs to be "fixed" to be usable. To acquire nitrogen, some plants (such as peas, beans and soy) have evolved symbiotic relationships with diazotrophs (nitrogen fixing bacteria and archaea). Many other plants (including the cereal crops such as corn, wheat and rice which supply 44% of the calories consumed globally) do not have such beneficial symbiotic relationships. Instead, these plants depend on synthetic nitrogen fertilizer to meet their needs. Synthetic fertilizer, however, is not environmentally or energetically sustainable. To overcome this, attempts have been made to bring biological nitrogen fixation methods to crops but have not been significantly successful. New methods of supplying nitrogen to plants are needed. To help meet this need, the inventors have developed a new biological approach. They have engineered diazotrophs to excrete nitrogen and thus increase the amount of bio-available nitrogen in the soil. This technology provides a more sustainable, environmentally-friendly method to provide crops with the nitrogen they need. https://techfinder.stanford.edu/technology_detail.php?ID=42972