Related Experiment Video
Updated: May 22, 2026
09:45
Laboratory Simulation of an Iron(II)-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
Disassembling iron availability to phytoplankton.
1Interuniversity Institute for Marine Sciences in Eilat Eilat, Israel.
Frontiers in Microbiology
|April 25, 2012
Summary
Iron bioavailability to phytoplankton is complex, influenced by speciation, physiology, and microbial interactions. This study clarifies iron acquisition mechanisms and proposes a spectrum of availability for better in situ growth assessment.
Area of Science:
- Ocean biogeochemistry and microbial ecology
- Phytoplankton physiology and iron acquisition
Background:
- Iron bioavailability is critical for marine primary production and carbon cycling, yet remains poorly defined.
- Limited iron supply to phytoplankton in oceans restricts primary productivity and atmospheric CO2 uptake.
- The concept of bioavailability is intricate, involving iron speciation, kinetics, phytoplankton physiology, and microbial interactions.
Purpose of the Study:
- To dissect the multifaceted concept of iron bioavailability to phytoplankton.
- To differentiate fundamental iron acquisition from complex ecological interactions.
- To explore the role of microorganisms in iron chemistry and bioavailability.
Main Methods:
- Synthesis of published and new data on iron bioavailability.
- Examination of phytoplankton's uptake pathways for free and organically bound iron.
- Analysis of uptake rate constants to compare iron-substrate availability across studies and environments.
Main Results:
- The reductive uptake pathway is pervasive in both prokaryotic and eukaryotic phytoplankton.
- Iron availability to phytoplankton is best viewed as a spectrum, not an absolute.
- Uptake rate constants effectively compare different iron sources and their contribution to phytoplankton growth.
- Microorganisms significantly influence iron chemistry through organic complexation and redox transformations.
Conclusions:
- Understanding iron bioavailability requires considering fundamental uptake and complex ecological factors.
- A spectrum approach and uptake rate constants offer a more nuanced view of iron availability for phytoplankton.
- Bio-modified iron species by microorganisms present unique bioavailability challenges and opportunities.
Keywords:
bioavailabilitybiogeochemistryironorganic complexationphytoplanktonredox reactionsspeciationuptakeMore Related Videos
07:03Measuring Photophysiology of Attached Stage of Colacium sp. by a Cuvette-Type Fast Repetition Rate Fluorometer
Published on: November 12, 2021
06:52Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria
Published on: December 19, 2017
Related Concept Videos
01:24Microbes and Other Elemental Cycles
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...
01:15Metabolism of Chemolithotrophs
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. However, because inorganic electron donors...
01:30Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
01:06Primary Production
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.
01:19Acid Mine Drainage
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 aquatic...
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...