化学と生物学の境界を乗り越え発展する窒素固定の科学

抄録

Nitrogen is essential for all living organisms. The Haber-Bosch process developed in the early 1900s currently produces ammonia from N₂ in the air and H₂ primarily derived from natural gas over a heterogeneous iron catalyst. Much of the ammonia is used to make agricultural fertilizers for food crops. However, this process requires high temperatures and pressures (ca. 500 ℃ and > 100 atm). In contrast, some nitrogenase-containing microbes are able to reduce N₂ to ammonia at ambient conditions. In the middle 1900s, science of both chemical and biological nitrogen fixation has begun to grow rapidly by cooperation between chemistry and biology towards more sustainable approaches to ammonia synthesis and elucidation of biological nitrogen fixation at molecular levels. This review summarizes the up-to-date research history and perspective of the growing science of nitrogen fixation, leading to development of new ways to nab nitrogen from the air to make fertilizers and produce organo-nitrogen compounds as well as the transfer of the nitrogen-fixing symbiosis to food crops like wheat and rice by plant biotechnology.