Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Metabolism of Chemolithotrophs01:15

Metabolism of Chemolithotrophs

719
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.
719
Microbial Nutrition01:28

Microbial Nutrition

1.0K
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...
1.0K
Overview of Nitrogen Metabolism01:20

Overview of Nitrogen Metabolism

10.9K
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...
10.9K
The Nitrogen Cycle01:49

The Nitrogen Cycle

59.3K
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...
59.3K
Inorganic Nitrogen Assimilation01:22

Inorganic Nitrogen Assimilation

428
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...
428
Redox Reactions01:27

Redox Reactions

840
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
840

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Genomic traits associated with copiotrophy decouple from maximum growth rate predictions along temperature gradients.

The ISME journal·2026
Same author

Dependency-competition tradeoffs structure microbial niches and nitrogen cycling.

ISME communications·2026
Same author

Mechanistic understanding of nitrate reduction as the dominant production pathway of nitrous oxide in marine oxygen minimum zones.

Nature communications·2025
Same author

Ecological dynamics explain modular denitrification in the ocean.

Proceedings of the National Academy of Sciences of the United States of America·2024
Same author

Nitrite-oxidizing bacteria adapted to low-oxygen conditions dominate nitrite oxidation in marine oxygen minimum zones.

The ISME journal·2024
Same author

Ammonia-oxidizing bacteria and archaea exhibit differential nitrogen source preferences.

Nature microbiology·2024

Related Experiment Video

Updated: Jan 8, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

6.5K

Redox-constrained microbial ecology dictates nitrogen loss versus retention.

Jemma Fadum1, Xin Sun1,2, Emily Zakem1

  • 1Division of Biosphere Sciences and Engineering, Carnegie Institution for Science, Stanford, CA 94305,  United States.

ISME Communications
|December 15, 2025
PubMed
Summary

Eutrophication shifts aquatic microbes from nitrogen loss to retention, amplifying the problem. Our model explains this transition, offering predictions for ecosystem management and microbial community analysis.

Keywords:
DNRAOMZanammoxanoxic environmentsdenitrificationnitrite reductionwater column

More Related Videos

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

9.1K
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
10:11

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Published on: August 3, 2016

10.3K

Related Experiment Videos

Last Updated: Jan 8, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

6.5K
Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

9.1K
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
10:11

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Published on: August 3, 2016

10.3K

Area of Science:

  • Microbial ecology
  • Biogeochemical cycling
  • Ecosystem modeling

Background:

  • Microorganisms are key drivers of biogeochemical cycles.
  • Eutrophication in aquatic systems with deep anoxic waters increases surface productivity, impacting anaerobic microbial communities.
  • Increased sinking organic carbon can shift microbial function from nitrogen loss to retention, creating a positive feedback loop that amplifies eutrophication.

Purpose of the Study:

  • To develop a quantitative, first-principles model of the transition from nitrogen loss to retention in anaerobic microbial communities.
  • To link microbial ecological dynamics to the energetics of microbial metabolisms.
  • To understand the impact of increasing organic carbon supply on nitrogen cycling.

Main Methods:

  • Developed and analyzed an ecosystem model incorporating redox chemistry.
  • Constrained traits of key anaerobic nitrogen-cycling microbial functional types: denitrification, dissimilatory nitrate reduction to ammonium, and anaerobic ammonium oxidation (anammox).
  • Linked ecological dynamics to microbial metabolism energetics.

Main Results:

  • The model successfully captures the transition from nitrogen loss to retention with increasing organic carbon supply.
  • Identified characteristics of microbial community composition at the "net zero N loss" point.
  • Provided testable hypotheses for sequencing data and other observations.

Conclusions:

  • The model offers a mechanistic understanding of nitrogen cycling shifts due to eutrophication.
  • Results provide a broadly applicable framework for predicting biogeochemical impacts of perturbations like eutrophication and deoxygenation.
  • Tying microbial ecology to environmental chemical potential enhances predictive capabilities for aquatic ecosystems.