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

The Equilibrium Constant03:10

The Equilibrium Constant

54.9K
Consider the oxidation of sulfur dioxide:
54.9K
States of Water01:23

States of Water

55.6K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
55.6K
2° Amines to N-Nitrosamines: Reaction with NaNO201:20

2° Amines to N-Nitrosamines: Reaction with NaNO2

5.2K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
5.2K
Primary Production01:06

Primary Production

24.9K
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.
24.9K
Quality of Water01:19

Quality of Water

427
In concrete preparation, the quality of water is paramount as it affects the strength and durability of the concrete. Potable water is usually preferred; however, it must not have excessive sodium or potassium to prevent compromising the concrete's integrity. Water quality is typically evaluated based on impurities such as dissolved solids, chlorides, and sulfates, and its pH value is ideally between 6 and 8. Even slightly acidic natural water may be acceptable unless it contains harmful...
427
Inorganic Nitrogen Assimilation01:22

Inorganic Nitrogen Assimilation

351
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...
351

You might also read

Related Articles

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

Sort by
Same author

Metabolic biochemical models of N<sub>2</sub> fixation for sulfide oxidizers, methanogens, and methanotrophs.

mSystems·2025
Same author

A global dataset of nitrogen fixation rates across inland and coastal waters.

Limnology and oceanography letters·2025
See all related articles

Related Experiment Video

Updated: Dec 15, 2025

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy
07:13

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy

Published on: February 25, 2021

4.3K

Upper Midwest lakes are supersaturated with N2.

Brianna M Loeks1, James B Cotner2

  • 1Department of Ecology Evolution and Behavior, University of Minnesota, St. Paul, MN 55108 loek0003@d.umn.edu.

Proceedings of the National Academy of Sciences of the United States of America
|July 8, 2020
PubMed
Summary

Freshwater lakes continuously release nitrogen gas to the atmosphere, challenging the idea that they primarily gain nitrogen. This suggests terrestrial inputs are crucial for balancing lake nitrogen cycles.

Keywords:
biogeochemistrydenitrificationnitrogen cyclingnitrogen fixation

More Related Videos

Author Spotlight: Understanding Riverine Nitrogen Impacts and Primary Productivity for Effective Nutrient Management
05:04

Author Spotlight: Understanding Riverine Nitrogen Impacts and Primary Productivity for Effective Nutrient Management

Published on: July 14, 2023

660
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: Dec 15, 2025

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy
07:13

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy

Published on: February 25, 2021

4.3K
Author Spotlight: Understanding Riverine Nitrogen Impacts and Primary Productivity for Effective Nutrient Management
05:04

Author Spotlight: Understanding Riverine Nitrogen Impacts and Primary Productivity for Effective Nutrient Management

Published on: July 14, 2023

660
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:

  • Environmental Science
  • Limnology
  • Biogeochemistry

Background:

  • Gaseous nitrogen (N2) exchange in freshwater systems is poorly understood.
  • N2 cycling is vital for aquatic ecosystems, involving nitrogen fixation and denitrification/anammox.
  • Atmospheric N2 exchange influences nutrient availability for aquatic life.

Purpose of the Study:

  • To investigate N2 saturation levels in lakes to infer net biological nitrogen processes.
  • To understand the role of N2 supersaturation in the nitrogen balance of freshwater systems.
  • To evaluate the prevailing paradigm of nitrogen fixation compensating for N-limitation in lakes.

Main Methods:

  • Analysis of N2 saturation in 34 lakes across a 5° latitude range.
  • Inclusion of lakes with diverse trophic statuses, mixing regimes, and bathymetry.
  • Statistical analysis of N2 supersaturation across a large sample size (n=248).

Main Results:

  • Nearly all surveyed lakes in the upper Midwest (USA) exhibited N2 supersaturation (>85% of samples).
  • This supersaturation indicates a net release of nitrogen from lakes to the atmosphere.
  • Observed N2 release suggests denitrification and/or anammox processes dominate over nitrogen fixation.

Conclusions:

  • Freshwater lakes are significant sources of atmospheric nitrogen, contrary to some traditional views.
  • The continuous loss of nitrogen implies that internal processes are not sufficient to balance the nitrogen cycle.
  • Terrestrial nitrogen inputs are likely essential for maintaining nitrogen balance in these lake ecosystems.