Related Experiment Video
Updated: Mar 31, 2026
10:49
Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading
Published on: March 6, 2014
17.9K
Fe-S interactions and geological background shape phosphorus bioavailability in mangrove sediments
Hong Xiang1, Yamin Deng2, Yuxiao Xu2
1MOE Key Laboratory of Groundwater Quality and Health & School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China; Institute of Geological Survey, China University of Geosciences, Wuhan, 430078, China.
Marine Pollution Bulletin
|March 29, 2026
Summary
Geological background influences phosphorus release from mangrove sediments. Volcanic soils release phosphorus via organic matter and iron-sulfur cycles, while coastal soils rely on microbial iron reduction.
Area of Science:
- Geochemistry
- Environmental Science
- Microbiology
Background:
- Mangrove sediments are crucial phosphorus sinks and sources in coastal zones.
- Bioavailable phosphorus (BAP) release is influenced by iron-sulfur-phosphorus (Fe-S-P) cycles.
- The role of geological background in mediating Fe-S-P coupling in mangroves is not well understood.
Purpose of the Study:
- To investigate how geological settings (volcanic weathering vs. Quaternary coastal) affect Fe-S-P interactions and phosphorus release in mangrove sediments.
- To compare phosphorus speciation and microbial communities in different geological zones.
- To identify distinct phosphorus release pathways based on geological context.
Main Methods:
- Fe-S-P fractionation analysis.
- Water-soluble organic matter (WSOM) fluorescence spectroscopy.
- Metagenomic sequencing.
Main Results:
- Total phosphorus is higher in volcanic weathering (V) sediments than Quaternary coastal (Q) sediments.
- Organic phosphorus (OP) dominates BAP in V sediments, linked to OP mineralization genes.
- Iron-bound phosphorus (Fe-P) dominates BAP in Q sediments, stabilized by iron oxides; Fe-P mobilization in deep V sediments is linked to Fe-S coupling, while in deep Q sediments, it's driven by microbial iron reduction.
Conclusions:
- Two distinct phosphorus release pathways exist: Fe-S-coupled regulation in volcanic zones and microbial iron reduction in coastal zones.
- Geological controls significantly mediate Fe-S-P interactions in mangrove sediments.
- Findings provide a basis for targeted phosphorus risk assessment and mangrove ecosystem management.
Related Concept Videos
01:21The Phosphorus Cycle
44.9K
Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, such as phosphate ions (PO43-), found in soil, water, sediment and rocks. Phosphorus is often a limiting nutrient (i.e., in short supply). Consequently, phosphorus is added to most agricultural fertilizers, which can cause environmental problems related to runoff in aquatic ecosystems.
44.9K
01:24Microbes and Other Elemental Cycles
61
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
61
01:42Phosphoinositides and PIPs
10.5K
Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
10.5K
01:25Microbial Bioremediation of Uranium
52
Microorganisms play a critical role in the transformation and immobilization of uranium in contaminated environments through four main pathways: bioreduction, biosorption, bioaccumulation, and biomineralization. These mechanisms reduce uranium’s toxicity and prevent its migration through groundwater systems, offering sustainable approaches for in situ bioremediation.Bioreduction of UraniumBioreduction is driven by anaerobic bacteria such as certain strains of Geobacter and Shewanella,...
52
01:20Sulfur Assimilation
494
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
494
01:19Acid Mine Drainage
51
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten...
51