Related Experiment Video
Updated: Dec 27, 2025
09:45
Laboratory Simulation of an IronII-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
12.2K
Pyrite-Based Cr(VI) Reduction Driven by Chemoautotrophic Acidophilic Bacteria
Xinxing Liu1, Haiyan Wu1, Min Gan1
1Department of Biology, Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
Frontiers in Microbiology
|March 3, 2020
Summary
This study shows that the bacteria Acidithiobacillus ferrooxidans enhances chromium (VI) reduction using pyrite, especially at low pH. This biological process offers an efficient method for remediating this priority pollutant.
Area of Science:
- Environmental Science
- Microbiology
- Geochemistry
Background:
- Chromium (VI) is a priority pollutant requiring effective remediation strategies.
- Pyrite is a potential substrate for Cr(VI) reduction, but its efficiency is pH-dependent.
- Biological augmentation can influence the Cr(VI) reduction process.
Purpose of the Study:
- To investigate the role of Acidithiobacillus ferrooxidans in driving pyrite-based Cr(VI) reduction.
- To understand the influence of pH on biological Cr(VI) reduction efficiency.
- To elucidate the mechanisms behind bacterial enhancement of Cr(VI) remediation.
Main Methods:
- Systematic investigation of pyrite-based Cr(VI) reduction.
- Inoculation with Acidithiobacillus ferrooxidans under varying pH conditions.
- Analysis of pyrite dissolution, reactive site regeneration, and secondary mineral formation.
Main Results:
- Cr(VI) reduction is highly proton-dependent, with optimal efficiency at pH 1-1.5.
- Acidithiobacillus ferrooxidans significantly enhanced Cr(VI) reduction efficiency.
- Bacteria promoted pyrite dissolution and reactive site regeneration, counteracting passivation effects.
Conclusions:
- Acidithiobacillus ferrooxidans-driven pyrite-based Cr(VI) reduction is an effective and economical remediation method.
- Maintaining a balance between Cr(VI) reduction and bacterial activity is crucial for sustainability.
- Bacterial activity mitigates passivation and enhances Cr(VI) remediation in challenging pH environments.
Related Concept Videos
01:28Microbial Nutrition
940
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...
940
01:15Metabolism of Chemolithotrophs
649
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.
649
01:27Diversity of Archaea III
266
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like...
266
01:20Sulfur Assimilation
258
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...
258
01:30Anoxygenic Photosynthesis
991
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...
991
01:28Anoxygenic Phototrophic Bacteria
657
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...
657