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T-00350: Nitrogen fixing bacterial endophyte


Many current and potential crops are unable to fix nitrogen through the traditional symbiotic relationship with rhizobia bacteria. Therefore expensive fixed nitrogen fertilizers must be applied to these crops. Endophytes are bacteria and fungi that grow within plants without causing disease symptoms, and in many cases can have beneficial effects on plant health and/or growth. Nitrogen fixing bacterial endophytes would be an economic and self-sustainable vehicle to provide fixed nitrogen nutrient to crops.


SDSU researchers have discovered that certain crops harbor bacteria containing genes capable of catalyzing the conversion of atmospheric nitrogen into ammonia, which can then be absorbed by plant for its growth. About 10 such endophytes have been isolated and identified. SDSU researchers are actively working on characterization of those endophytes and development of large scale inoculation methods for commercial application.


Nitrogen fixing endophytes are an efficient, economic and environment-friendly approach to provide nitrogen nutrient to crops. Nitrogen fixed by endophytes is almost 100% available to the plant they grow within, therefore greatly reducing the possibility of fixed nitrogen being washed off plant and polluting water bodies. This nitrogen would be produced and available throughout the growing season, therefore reducing or eliminating the need of expensive chemically synthesized nitrogen. Moreover, endophytes have also been shown to provide other health benefits to their host plant.