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

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.

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...

Inorganic Nitrogen Assimilation

Inorganic Nitrogen Assimilation

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...

Environmental Applications of Microorganisms

Environmental Applications of Microorganisms

Microorganisms play a pivotal role in maintaining ecosystem balance by recycling essential elements such as carbon, nitrogen, and phosphorus, as well as supporting processes like bioremediation, wastewater treatment, and biofuel production.Microbes in Elemental CyclesIn the carbon cycle, microorganisms decompose organic matter, releasing carbon dioxide via aerobic respiration. This carbon dioxide is subsequently used by photosynthetic organisms to synthesize organic compounds, closing the...

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...

Carbon-dioxide Fixation

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...

You might also read

Related Articles

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

Sort by

Same author

Volcanic eruptions caused weakening AMOC during the preindustrial past millennium.

Nature communications·2026

Same author

Algal organelle integrity-based high-throughput alternative to conventional bioassay for whole wastewater toxicity testing.

Water research·2026

Same author

Instrumental activity of daily living combined with glycated hemoglobin predict cardiovascular disease.

Nutricion hospitalaria·2026

Same author

Pore Wall Engineered Covalent-Organic Frameworks as Size-Matched Nanotraps Enable Highly Selective Adsorption of Sulfonamide Antibiotics.

Environmental science & technology·2026

Same author

Geopolymer-based composite filtration materials for deep purification of wastewater: Efficient nitrogen removal and emerging contaminants elimination.

Environmental research·2026

Same author

Associations of novel visceral obesity indices (METS-VF and BRI) with dementia: the role of metabolic mediators and genetic susceptibility.

Frontiers in nutrition·2026

Search research articles

Related Experiment Video

Updated: Mar 2, 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

Denitrification using excess activated sludge as carbon source: Performance and the microbial community dynamics.

Haohao Sun¹, Qiang Wu¹, Ping Yu²

¹State Key Laboratory of Pollution Control and Resource Reuse, Environmental Health Research Center, School of the Environment, Nanjing University, Nanjing 210023, China.

Bioresource Technology

|May 10, 2017

Summary

Excess activated sludge effectively removes nitrate from wastewater using an optimized anaerobic reactor. This sustainable method achieves low nitrate levels (<1mgL-1), enhancing wastewater treatment processes.

Keywords:

Denitrification Excess activated sludge High-throughput sequencing WWTP effluent

More Related Videos

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Published on: October 15, 2015

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: Mar 2, 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

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Published on: October 15, 2015

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:

Environmental Science
Microbiology
Wastewater Treatment Engineering

Background:

Nitrate contamination in wastewater poses environmental risks.
Conventional denitrification methods require external carbon sources.
Utilizing waste sludge as a carbon source offers a sustainable alternative.

Purpose of the Study:

To investigate the feasibility of using excess activated sludge as an internal carbon source for denitrification.
To optimize an upflow anaerobic reactor for efficient nitrate removal.
To analyze the impact of sludge addition on nitrogen removal efficiency.

Main Methods:

Operation of an optimized upflow anaerobic reactor.
Testing with synthetic and real municipal wastewater.
Analysis of nitrate nitrogen reduction and total nitrogen removal.
16S rRNA gene high-throughput sequencing for bacterial community analysis.

Main Results:

Achieved high denitrification performance, reducing nitrate nitrogen to below 1 mg/L within a 6-hour hydraulic retention time.
Total nitrogen removal efficiency increased with the amount of sludge added.
Nitrogen removal per unit of added sludge decreased with increasing sludge dosage.
Observed shifts in bacterial communities, with a decrease in Pseudomonas and Thauera, indicating their role in organic matter release.

Conclusions:

Excess activated sludge is a feasible and effective internal carbon source for denitrification.
The optimized upflow anaerobic reactor demonstrates high efficiency in removing low concentrations of nitrate.
Bacterial community dynamics play a crucial role in sludge digestion and organic matter release for denitrification.