Electron Acceptor

Microorganisms such as bacteria obtain energy to grow by transferring electrons from an electron donor to an electron acceptor. An electron acceptor is a compound that receives or accepts an electron during cellular respiration. The microorganism through its cellular machinery collects the energy for its use. The process starts with the transfer of an electron from an electron donor. During this process (electron transport chain) the electron acceptor is reduced and the electron donor is oxidized. Examples of acceptors include oxygen, nitrate, iron (III), manganese (IV), sulfate, carbon dioxide, or in some cases the chlorinated solvents such as tetrachloroethene (PCE), trichloroethene (TCE), dichloroethene (DCE), and vinyl chloride (VC). These reactions are of interest not only because they allow organisms to obtain energy, but also because they are involved in the natural biodegradation of organic contaminants. When clean-up professionals use monitored natural attenuation to clean up contaminated sites, biodegradation is one of the major contributing processes.

Toxics Program Remediation Related Microbial Activities

• RDX Biodegradation Assessment, Naval Submarine Base Bangor, Washington
• Quantifying Subsurface Biodegredation
• Can Trees Clean Up Ground Water? Phytoremediation of Trichloroethene-Contaminated Ground Water at Air Force Plant 4, Fort Worth, Texas
• Natural Attenuation of Wood Preservatives in Ground Water
• Natural Aquifer Restoration
• Quantifying Natural Attenuation at the Plume Scale

Information on Toxics Program Microbiological Investigations

• RDX Biodegradation Under Metal-Reducing Conditions
• Processes that Control the Natural Attenuation of Chlorinated Solvents
• Microbial Degradation of Chloroethenes in Ground Water Systems
• Application of Molecular Methods in Microbial Ecology to Understand the Natural Attenuation of Chlorinated Solvents
• New Microorganism Discovered that Survives on Arsenic in an Extremely Harsh Environment
• History and Ecology of Chloroethene Biodegradation–A Review
• The Changing Face of Microbial Communities in Contaminant Plumes
• Microbiology and Molecular Ecology of Biogeochemical Cycles in Aquatic Environments
• Bacteria-Contaminant Interactions
• Organic Compounds in Near-Surface Environments: Understanding Fate in a Changing Biogeochemical Landscape
  

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