Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

The Nitrogen Cycle

The Nitrogen Cycle

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...

Bioremediation

Bioremediation

Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins in groundwater as a byproduct of agricultural run-off and also to clean up oil spills.

Overview of Nitrogen Metabolism

Overview of Nitrogen Metabolism

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 nitrogen...

Metabolism of Chemolithotrophs

Metabolism 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...

Microbes and the Nitrogen Cycle

Microbes and the Nitrogen Cycle

The nitrogen cycle is a complex biogeochemical process critical to maintaining the balance of nitrogenous compounds in ecosystems. This cycle involves multiple microbial-mediated transformations through which nitrogen changes oxidation states, supporting essential ecological functions and contributing to plant and microbial growth.Nitrogen Fixation and AmmonificationNitrogen fixation initiates the cycle by converting inert atmospheric nitrogen (N₂) into bioavailable ammonia (NH₃), a process...

Microbial Wastewater Treatment

Microbial Wastewater Treatment

Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.

You might also read

Related Articles

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

Sort by

Same author

Pure and Oxidized Copper Materials as Potential Antimicrobial Surfaces for Spaceflight Activities.

Astrobiology·2017

Same author

Increasing antiviral activity of surfactant protein d trimers by introducing residues from bovine serum collectins: dissociation of mannan-binding and antiviral activity.

Scandinavian journal of immunology·2010

Same author

The effects of androgen treatment upon embryonic male hamsters.

The Anatomical record·2010

Same author

The impact and recovery of asteroid 2008 TC(3).

Nature·2009

Same author

Multiple components contribute to ability of saliva to inhibit influenza viruses.

Oral microbiology and immunology·2009

Same author

Inhibition of influenza viral neuraminidase activity by collectins.

Archives of virology·2007

Search research articles

Related Experiment Video

Updated: Jul 26, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

Published on: December 25, 2015

Controlling denitrification in closed artificial ecosystems.

R L Mancinelli¹, D T Smernoff, M R White

¹NASA-Ames Research Center, Moffett Field, CA 94035, USA.

Advances in Space Research : the Official Journal of the Committee on Space Research (COSPAR)

|September 7, 2001

Summary

Denitrification, the microbial conversion of nitrate to nitrogen gas, occurs even in oxygen-rich closed systems. This study shows Pseudomonas fluorescens denitrifies under aerobic conditions, impacting closed system efficiency.

Keywords:

NASA Center ARC NASA Discipline Life Support Systems

More Related Videos

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Estimating Sediment Denitrification Rates Using Cores and N₂O Microsensors

Published on: December 6, 2018

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

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

Related Experiment Videos

Last Updated: Jul 26, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

Published on: December 25, 2015

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Estimating Sediment Denitrification Rates Using Cores and N₂O Microsensors

Published on: December 6, 2018

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

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

Area of Science:

Microbiology
Environmental Science
Biotechnology

Background:

Denitrification is the microbial reduction of nitrate to gaseous nitrogen forms (N2O, N2).
Closed artificial systems, like plant growth chambers, experience nitrogen loss via denitrification.
Denitrification reduces system efficiency and releases nitrous oxide (N2O), a greenhouse gas.

Purpose of the Study:

To investigate the effect of oxygen levels on denitrification in closed systems.
To study the population growth of Pseudomonas fluorescens under varying oxygen conditions.
To assess the potential of Pseudomonas fluorescens to mitigate denitrification in closed environments.

Main Methods:

Utilized Pseudomonas fluorescens (ATCC # 17400) as a model organism.
Grew the bacteria in a two-liter bioreactor under controlled, varying oxygen levels.
Monitored population growth and denitrification rates in response to oxygen availability.

Main Results:

Denitrification was observed in the closed system even under conditions considered aerobic.
Pseudomonas fluorescens exhibited denitrification despite sufficient oxygen supply and rapid gas turnover.
Oxygen levels significantly influence bacterial growth and denitrification activity in closed systems.

Conclusions:

Denitrification can occur in well-mixed, oxygen-rich closed systems, contrary to common assumptions.
Pseudomonas fluorescens actively denitrifies under aerobic conditions, posing challenges for closed system management.
Understanding oxygen's role is crucial for controlling denitrification and optimizing closed artificial ecosystems.