一个单细胞的蓝藻细菌依赖的能量来固定N2
Si Tang1, Xueyu Cheng1, Yaqing Liu1
1Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Tsinghua Shenzhen International Graduate School, Shenzhen, Guangdong Province, PR China.
Nature communications
|November 9, 2024
概括
半性蓝藻细菌需要离子,而不仅仅是气,以固定. 低度的酸盐通过防止沿海蓝藻细菌产生足够的能量来抑制固.
科学领域:
- 海洋微生物学 海洋微生物学
- 生物地质化学生物地质化学
- 蓝藻细菌生理学 蓝藻细菌生理学
背景情况:
- 半型蓝藻细菌对于海洋生态系统中固定至关重要.
- 它们在气有限的沿海水域中的稀缺性构成了生态悖论.
- 假设高盐度可以抑制固.
研究的目的:
- 研究盐度和离子在沿海蓝藻细菌固中的作用.
- 了解固的生理机制,以应对的可用性.
主要方法:
- 在Cyanothece sp.的培养中. 在不同的NaCl度下,ATCC 51142 (Crocosphaera subtropica) 在不同的NaCl度下.
- 测量气 (N2) 的固定速率.
- 对 nifHDK 基因表达和酶合成的分析.
- 评估细胞ATP水平和代谢途径.
主要成果:
- 在低NaCl度 (<4g/L) 和依赖离子的情况下,固被抑制.
- 在没有Na+的情况下,nifHDK基因被上调,酶被合成,但N2的固定和生长停止了.
- 2固定的损失与ATP供应不足有关.
- 固化似乎是由能量和混合酸发酵驱动的,而不是质子能量.
结论:
- 离子,而不仅仅是盐度,对于这个沿海蓝藻细菌的固定至关重要.
- 能量代谢,特别是通过能量和发酵提供ATP,是N2固定的关键.
- 这些发现挑战了关于盐度抑制的先前假设,并突出了新的能源合机制.
相关概念视频
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
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
The Nitrogen Cycle
51.6K
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...
51.6K
Bacterial Phylum Cyanobacteria
Cyanobacteria are a diverse group of oxygenic, phototrophic bacteria that played a pivotal role in converting Earth’s atmosphere from anoxic to oxygen-rich billions of years ago. They exhibit remarkable morphological diversity, ranging from unicellular forms to filamentous types, with cell sizes varying between 0.5 μm and 100 μm. Cyanobacteria are classified into five groups: Chroococcales (unicellular, dividing by binary fission), Pleurocapsales (unicellular, dividing by...
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
Microbial Nutrition
1
Organisms exhibit remarkable metabolic diversity, categorized based on how they acquire energy and carbon. These strategies enable survival in various ecological niches and are essential for maintaining energy flow and nutrient cycling within ecosystems.Energy and Carbon SourcesOrganisms are classified as phototrophs or chemotrophs based on energy acquisition. Phototrophs use light as their energy source, while chemotrophs rely on oxidizing chemical compounds. Further differentiation arises...
1


