Related Experiment Video
Updated: Jul 17, 2026
06:52
Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria
Published on: December 19, 2017
Beyond arsenite: Arsenite-oxidizing prokaryotes drive sulfur compound oxidation
Chengsheng Yang1, Yifan Xu1, Yao Nie1
1State Key Laboratory of Geomicrobiology and Environmental Changes & School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
Bioresource Technology
|July 15, 2026
Summary
Arsenite oxidation prokaryotes (AsOPs) oxidize toxic arsenic and reduced sulfur compounds. This dual activity can cause significant environmental acidification, requiring caution during arsenic bioremediation applications.
Area of Science:
- Environmental Microbiology
- Biogeochemistry
- Arsenic Bioremediation
Background:
- Arsenite oxidation prokaryotes (AsOPs) are crucial for arsenic cycling and bioremediation.
- AsOPs reduce arsenic toxicity by oxidizing As(III) to As(V).
- Potential co-metabolic activities of AsOPs remain underexplored, especially concerning co-contaminants like sulfur.
Purpose of the Study:
- To investigate whether AsOPs possess catalytic activities beyond arsenite oxidation.
- To determine if AsOPs can oxidize reduced sulfur compounds.
- To assess the implications of these activities on arsenic bioremediation strategies.
Main Methods:
- Enrichment culture of AsOPs.
- Metagenomic analysis of AsOP communities.
- Functional assays on AsOP communities and strains.
- Analysis of sulfide oxidation, nitrate reduction, and pH changes.
- Investigation of arsenopyrite degradation.
Main Results:
- Metagenomic analysis showed >96% of AsOP MAGs possess sulfur oxidation pathways.
- AsOPs actively catalyzed anaerobic sulfide oxidation coupled with nitrate reduction, producing sulfate and causing significant pH drop.
- AsOPs degraded arsenopyrite, releasing As(V) and sulfate, leading to severe acidification (pH 2.5).
Conclusions:
- AsOPs exhibit significant anaerobic reduced sulfur compound oxidation activity.
- This activity, alongside arsenite oxidation, can lead to substantial environmental acidification.
- Extreme caution is advised when deploying AsOPs for arsenic bioremediation due to potential unintended acidification.
Related Concept Videos
01:29Microbes and the Sulfur Cycle
Sulfur is a vital element in Earth's biogeochemical systems. It transitions through various inorganic states, including sulfate (SO₄²⁻), elemental sulfur (S⁰), and sulfide (S²⁻). Abiotic and biological mechanisms across oxic and anoxic environments intricately mediate these transformations. Sulfate, the most oxidized form of sulfur, is predominantly stored in rocks, marine sediments, and oceanic waters, acting as a long-term reservoir in the global sulfur cycle.In oxic environments,...
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...
01:20Sulfur Assimilation
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 become...
01:19Acid Mine Drainage
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten aquatic...
01:24Microbes and Other Elemental Cycles
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
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...