Related Experiment Video
Updated: Jul 4, 2026
07:34
Biogas Purification through the use of a Microalgae-Bacterial System in Semi-Industrial High Rate Algal Ponds
Published on: March 22, 2024
Microalgae-Mediated Electron Transfer and Allocation in Paracoccus denitrificans for Efficient Nitrate Removal
Yue Li1, Chungui Yu1, Shiyu Miao1,2
1Center for Water and Ecology, State Key Laboratory of Iron and Steel Industry Environmental Protection, School of Environment, Tsinghua University, Beijing 100084, China.
Environmental Science & Technology
|July 2, 2026
Summary
Microalgae enhance nitrate removal by bacteria through non-nutritional signaling. This interaction optimizes bacterial metabolism, boosting electron transfer for efficient nitrate conversion and environmental remediation.
Area of Science:
- Environmental microbiology
- Biotechnology
- Biogeochemical cycles
Background:
- Microalgal-bacterial systems show potential for enhanced nitrate removal.
- The precise regulatory mechanisms, especially non-nutritional ones, are not fully understood.
Purpose of the Study:
- To elucidate the molecular mechanisms underlying enhanced nitrate removal in microalgal-bacterial co-cultures.
- To investigate the non-nutritional interactions between *Chlorella vulgaris* (*C. vulgaris*) and *Paracoccus denitrificans* (*P. denitrificans*).
Main Methods:
- Transcriptomic analysis of *P. denitrificans* co-cultured with *C. vulgaris*.
- Measurement of NADH production and electron transport chain (ETC) gene expression.
- Analysis of ammonium and glutamate dynamics between species.
Main Results:
- *C. vulgaris* significantly increased the nitrate removal rate constant by 2.48-fold.
- Co-culture upregulated glycolytic and ETC genes in *P. denitrificans*, increasing NADH production and activating the ETC.
- Bacterial ammonium induced microalgal glutamate synthesis, which signaled to upregulate bacterial nitrate reductase.
- Carbon utilization efficiency for nitrate removal increased by 82.75%.
Conclusions:
- Microalgae optimize bacterial carbon and nitrogen metabolism through molecular signaling.
- This reprogramming enhances electron generation, transfer, and allocation for efficient nitrate conversion.
- Provides mechanistic insights for designing microalgal-bacterial systems for environmental remediation.
Keywords:
carbon metabolismelectron transport chainlactatemicroalgal-bacterial systemnitrate removalwater treatmentMore Related Videos
10:20Quantification of Heavy Metals and Other Inorganic Contaminants on the Productivity of Microalgae
Published on: July 10, 2015
08:05Measurement 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 Concept Videos
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...
01:30Anoxygenic Photosynthesis
Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green sulfur bacteria, heliobacteria, and...
01:28Microbial Nutrition
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...
01:25Biofuels
The microbial conversion of organic matter into biofuels holds potential as a renewable energy source. Among biofuel sources, microalgae are recognized as a highly efficient and adaptable feedstock for biodiesel production, owing to their rapid biomass accumulation, elevated lipid productivity, and capacity to proliferate in diverse aquatic systems, including freshwater, marine, and wastewater habitats. Unlike terrestrial crops, microalgae do not compete for land and can achieve significantly...
01:22Inorganic 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 nitrate reductase...
01:28Anoxygenic Phototrophic Bacteria
Anoxygenic phototrophic bacteria are a diverse group of microorganisms that perform photosynthesis without producing oxygen. They primarily include purple sulfur bacteria, purple nonsulfur bacteria, green sulfur bacteria, and green nonsulfur bacteria. These bacteria are classified into the Gammaproteobacteria, Alphaproteobacteria, Betaproteobacteria, Chlorobi, and Chloroflexi lineages, each with distinct physiological and ecological adaptations.Purple sulfur bacteria belong to the...