氧化在氧化氨酸氧化过程中所起的作用 氧化氨酸氧化细菌的作用
Eunkyung Choi1, Sana I Chaudhry1, Willm Martens-Habbena1
1Fort Lauderdale Research and Education Center, Microbiology & Cell Science Department, University of Florida, Davie, Florida, USA.
Applied and environmental microbiology
|July 13, 2023
概括
氧化 (NO) 在细菌氧化氨中起作用. 这项研究表明,NO主要在氧气有限的条件下产生,并被PTIO清理,影响氧化的产生.
科学领域:
- 环境微生物学 环境微生物学
- 生物地质化学循环的过程
背景情况:
- 细菌对氨的氧化对循环至关重要,有助于温室气体排放.
- 亚氧化物 (NO) 在氨氧化中的作用受到争论,并提出其作为中间体或氧化剂的作用.
- 低度的NO使其代谢难以在氨氧化细菌 (AOB) 中研究.
研究的目的:
- 研究在模型AOB菌株*Nitrosomonas europaea*中氨氧化过程中氧化 (NO) 的作用和产生的情况.
- 用电化学传感器和轻度的NO清理器来量化低微分子度的NO生产率.
- 确定氧气供应对NO代谢的影响及其与氧化 (N2O) 生产的关系.
主要方法:
- 使用电化学传感器测量明显的NO度.
- 采用了NO吸尘器2--4,4,5,5-四甲基利米达-1-3-氧化物 (PTIO) 来量化NO的生产率.
- 在*N. europaea*中,在充氧和有限氧的生长条件下,比较了NO生产和N2O生成.
主要成果:
- 在*N. europaea*和*Nitrosospira briensis*中,PTIO有效地清除了NO,但没有抑制氨氧化.
- 在充氧条件下,N. europaea*的NO生产占化物生产的3.15%至6.23%.
- 在氧气限制下,NO产量显著增加 (高达亚酸盐产量的40%),PTIO添加取消了N2O产量.
结论:
- 氧化 (NO) 主要是在AOB的氧气有限条件下的氨氧化过程中产生的.
- PTIO作为自由NO的特定清除剂,表明NO在正常情况下可能与酶紧密结合.
- 这些发现表明,NO与氧胺脱酶的分离与氨和和和适应氧气限制有关,影响N2O排放.
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