Denitrification in hypersaline and coastal environments
Javier Torregrosa-Crespo1, Jose María Miralles-Robledillo1, Eric Bernabeu1
1Biochemistry and Molecular Biology, and Edaphology and Agricultural Chemistry Department, Faculty of Sciences, University of Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Alicante, Spain.
FEMS Microbiology Letters
|July 8, 2023
Summary
Salinity impacts denitrifier distribution in coastal ecosystems, though mechanisms remain debated. This review analyzes studies on salt gradients and microbial communities, discussing denitrifier types and research methods.
Area of Science:
- Environmental Microbiology
- Ecosystem Ecology
- Biogeochemistry
Background:
- Denitrification is crucial for nitrogen removal and linked to global warming.
- Studies increasingly examine denitrifier distribution across diverse environments.
- Coastal saline ecosystems are key areas for understanding these processes.
Purpose of the Study:
- To analyze the relationship between denitrification and salinity gradients in coastal environments.
- To review the distribution patterns of denitrifiers influenced by salinity.
- To discuss the prevalence of different denitrifier types (nirS/nirK) and influencing factors.
Main Methods:
- Literature and database analysis of reported studies.
- Examination of research focused on estuaries, mangroves, and hypersaline ecosystems.
- Discussion of techniques used to analyze denitrifier distribution along salt gradients.
Main Results:
- Salinity directly affects denitrifier distribution, though some studies present conflicting results.
- NirS type nitrite reductase is generally found in mesohaline environments, while NirK predominates in hypersaline ones.
- Various physical and chemical parameters, besides salinity, influence denitrifying microbial communities.
Conclusions:
- The precise mechanisms of salinity's influence on denitrifier distribution require further investigation.
- Standardized research approaches are needed for robust comparative analysis.
- Understanding denitrifier dynamics in saline environments is vital for ecosystem management and climate change mitigation.
Related Concept Videos
01:15Metabolism of Chemolithotrophs
52
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.
52
01:28Carbon-dioxide Fixation
42
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...
42
01:22Inorganic Nitrogen Assimilation
49
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...
49
02:02Responses to Salt Stress
13.2K
Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.
13.2K
01:20Overview of Nitrogen Metabolism
8.2K
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...
8.2K
01:06Primary Production
23.7K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
23.7K