海洋固中的未解之
Jonathan P Zehr1, Douglas G Capone2
1Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA.
Trends in microbiology
|September 1, 2023
概括
生物固定对海洋生产力至关重要,但许多问题仍然存在. 研究突出了三氏体和非蓝藻细菌的复杂作用在海洋循环中.
科学领域:
- 海洋微生物生态学
- 生物地质化学循环是什么
- 海洋学 海洋学 海洋学
背景情况:
- 生物 (N2) 固定对全球生物地球化学循环和海洋生产力至关重要.
- 关键的固有机体,如三甲和微生物相互作用的作用仍然不太清楚.
- 在海洋循环中,非菌性阴性菌体 (NCDs) 的重要性代表了大量的知识缺口.
研究的目的:
- 解决尚未解决的问题,并挑战生物固化的现有范式.
- 为了探索Trichodesmium和其他海洋类动物的复杂生态作用.
- 突出进一步研究微生物相互作用和非传染性疾病的需要,以了解海洋营养循环.
主要方法:
- 审查和综合目前关于海洋固化的研究.
- 对Trichodesmium和非蓝色细菌的二氧化菌现有数据的分析.
- 识别知识缺口和未来研究领域.
主要成果:
- 海洋中输入和损失的基本平衡尚未完全解决.
- 海洋固定涉及复杂的微生物相互作用,包括微生物组和共生,超出自由生活的蓝藻细菌.
- 酶基因在非传染性疾病中的流行程度表明,它们对海洋循环有着重要的,但尚未定量化的贡献.
结论:
- 了解海洋循环需要解决有关输入-损失平衡和多种多样性动物的角色的基本问题.
- 对Trichodesmium和非传染性疾病的生物学和生态学的进一步研究,包括它们的相互作用,至关重要.
- 解决这些知识差距对于预测海洋对环境变化的反应及其对全球N和C循环的影响至关重要.
相关概念视频
01:22Inorganic Nitrogen Assimilation
44
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...
44
01:28Carbon-dioxide Fixation
37
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...
37
01:20Overview of Nitrogen Metabolism
8.1K
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...
8.1K
01:15Metabolism of Chemolithotrophs
40
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.
40
01:49The Nitrogen Cycle
52.7K
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...
52.7K
01:30Anoxygenic Photosynthesis
50
Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green...
50