Related Experiment Video
Updated: Feb 28, 2026
05:29
Self-standing Electrochemical Set-up to Enrich Anode-respiring Bacteria On-site
Published on: July 24, 2018
8.2K
Acetate production and electron utilization facilitated by sulfate-reducing bacteria in a microbial electrosynthesis
Yinbo Xiang1, Guangli Liu1, Renduo Zhang1
1Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Bioresource Technology
|June 21, 2017
Summary
Adding sulfate-reducing bacteria significantly boosted acetate production and electron harvesting in microbial electrosynthesis systems (MES). This enhancement was most notable at -0.7V, improving performance by over twofold.
Area of Science:
- Environmental Science
- Microbiology
- Electrochemistry
Background:
- Microbial electrosynthesis (MES) systems offer a promising avenue for sustainable chemical production.
- Optimizing MES performance is crucial for efficient resource recovery and biosynthesis.
- The role of specific microbial groups, like sulfate-reducing bacteria, in MES performance requires further investigation.
Purpose of the Study:
- To investigate the impact of sulfate-reducing bacteria (SRB) on the performance of a mixed-culture microbial electrosynthesis system (MES).
- To evaluate the effect of different cathode potentials and sulfate addition on acetate production and electron harvesting in MES.
- To analyze the changes in microbial community structure and electrochemical activity of the cathode biofilm.
Main Methods:
- Two-chamber MES reactors were operated at various cathode potentials (-0.5 to -0.8V).
- Sulfate was added at a concentration of 6mM to assess its effect on MES performance.
- Acetate production, electron harvesting, biomass, cell viability, and microbial community composition (using relative abundance of key genera) were quantified.
Main Results:
- Acetate production and electron harvesting were significantly enhanced with sulfate addition, particularly at -0.7V (2.7-fold and 2.4-fold increases, respectively).
- The presence of sulfate increased biomass, live cell proportion, and electrochemical activity of the cathode biofilm across all tested potentials.
- At -0.7V, the relative abundance of Desulfovibrionaceae increased substantially with sulfate addition, while Acetobacterium showed a slight decrease, indicating a shift in microbial community dynamics.
Conclusions:
- Sulfate-reducing bacteria play a beneficial role in enhancing the performance of mixed-culture MES, particularly in acetate production and electron transfer.
- Optimal cathode potential, in conjunction with SRB activity, can significantly improve the efficiency of MES for valuable chemical synthesis.
- The findings highlight the potential of manipulating microbial communities, specifically by including SRB, to optimize MES-based bioproduction.
Related Concept Videos
01:20Sulfur Assimilation
434
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
434
01:15Metabolism of Chemolithotrophs
1.0K
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.
1.0K
01:30Anoxygenic Photosynthesis
1.5K
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...
1.5K
01:28Microbial Nutrition
1.7K
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...
1.7K
02:36The Citric Acid Cycle
163.5K
The citric acid cycle, also known as the Krebs cycle or TCA cycle, consists of several energy-generating reactions that yield one ATP molecule, three NADH molecules, one FADH2 molecule, and two CO2 molecules.
163.5K
01:28Carbon-dioxide Fixation
778
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...
778