Physiology of Hydrogen Oxidation and Terminal Oxidases in Azotobacter vinelandii

维氏固氮菌中氢氧化和末端氧化酶的生理学

• 批准号: 8804047
• 负责人: Robert Maier
• 金额: $ 12.3万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-09-01 至 1992-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8804047&HistoricalAwards=false
• 关键词: Physiology; Hydrogen; Oxidation; Terminal; Oxidases

The energy-consuming biological nitrogen fixation process is essential for a positive input of usable nitrogen on earth. The ATP-dependent evolution of hydrogen by nitrogenase results in a considerable loss of energy from the nitrogen fixation process. However, the evolved hydrogen can be recycled via an hydrogen oxidizing electron transport system. The cytochrome components involved in hydrogen oxidation and the role they play in protecting nitrogenase from oxygen damage, and supplying ATP to nitrogenase are poorly understood. This research uses mutant analyses approaches toward understanding and assessing the roles of terminal oxidases in nitrogen fixation and various substrate oxidations using Azotobacter vinelandii. The approaches include the isolation and characterization of mutants with deletions in cytochrome o and d genes.%%% Increasing world population combined with dwindling fuel reserves makes increased dependence on nitrogen fixation likely. Since most experts believe that the nitrogen fixation process is energy (ATP) limited, factors that result in efficient use of otherwise wasted energy (such as hydrogen) deserve research attention. Hydrogen oxidation by the bacterium Azotobacter has been shown to allow the nitrogen fixing enzyme to function optimally. The study of hydrogen-oxidizing electron transport and its regulation shows promise for increasing nitrogen fixation.***//

耗能生物固氮工艺， 这对地球上可用氮的积极输入至关重要。 固氮酶依赖ATP的放氢 导致来自氮气的相当大的能量损失 固定过程。 然而，释放的氢可以是 通过氢氧化电子传递系统再循环。 参与氢氧化的细胞色素成分， 它们在保护固氮酶不受氧气影响中所起的作用 伤害，为固氮酶提供ATP的能力差 明白 本研究使用突变分析方法 了解和评估终端的作用 固氮氧化酶和各种底物 使用棕色固氮菌进行氧化。 的方法 包括突变体的分离和表征， 细胞色素o和d基因缺失。% 世界人口增加加上燃料减少 储量增加对固氮的依赖 很有可能。 因为大多数专家认为 固定过程是能量（ATP）有限的，导致 在有效利用否则浪费的能量（例如， 氢）值得研究关注。 氢氧化， 固氮菌已经被证明可以 固氮酶发挥最佳功能。 研究 氢氧化电子传递及其调控 显示出增加固氮的前景。***//