通过酸盐化Geobacteraceae的前所未有的N2O生产,具有独特的N2O同位素特征
Zhenxing Xu1,2, Shohei Hattori3,4, Yoko Masuda2,5
1Marine College, Shandong University, Weihai, China.
mBio
|October 30, 2024
概括
分离性酸盐降解为 (DNRA) 通过Geobacteraceae细菌的两个新途径产生氧化 (N2O). 这些通路具有独特的同位素特征,可以更好地追踪土壤中的N2O来源.
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
- 温室气体排放量 温室气体排放量
背景情况:
- 分离性酸盐降解为 (DNRA) 是陆地生态系统中一个关键的循环路径.
- DNRA可以产生氧化物 (N2O),这是一个强大的温室气体,但DNRA衍生的N2O的机制和识别是不太了解的.
- 地细菌是米土壤中占主导地位的酸盐氨化细菌,这表明它们在N2O生产中的作用.
研究的目的:
- 在Geobacteraceae中描述N2O生产的新型酶途径.
- 识别DNRA衍生N2O的独特同位素特征,以区分其与其他来源.
- 了解DNRA对农业土壤N2O排放的贡献.
主要方法:
- 在Geobacteraceae菌株上进行酶分析,以确定N2O生产途径.
- 分析来自不同途径的N2O同位素特征 (15N位点偏好).
- 在Nar缺乏和野生型菌株中对N2O生产机制的比较分析.
主要成果:
- 在Geobacteraceae中确定了两个新的N2O生产途径:一个涉及Nar和Hcp-Hcr,另一个涉及使用NrfA和Hcp-Hcr的Nar缺乏菌株.
- 对于DNRA衍生的N2O,观察到独特的同位素特征,特别是高的15N位点偏好值 (43.0‰-49.9‰).
- 这些酶组合 (Nar/Hcp-Hcr和NrfA/Hcp-Hcr) 在细菌中广泛存在.
结论:
- 在Geobacteraceae中阐明了两个新的与DNRA相关的N2O生产途径.
- 独特的同位素特征为环境中N2O来源的分离提供了可靠的方法.
- 了解这些途径对于管理N2O排放和提高农业中使用效率至关重要.
相关概念视频
Metabolism of Chemolithotrophs
2
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation.
2
Overview of Nitrogen Metabolism
7.8K
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
7.8K
Inorganic Nitrogen Assimilation
5
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
5
2° Amines to N-Nitrosamines: Reaction with NaNO2
4.1K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.1K
Carbon-dioxide Fixation
1
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
1
The Nitrogen Cycle
51.7K
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
51.7K


