Geobacter

A genus of bacteria known for its electron transfer capabilities

Geobacter is a genus of Proteobacteria belonging to the family Geobacteraceae. These bacteria are known for their ability to transfer electrons to metals and other solid surfaces, a process that is significant in the biogeochemical cycling of metals and in bioremediation.

Characteristics

Geobacter species are anaerobic and gram-negative bacteria. They are rod-shaped and motile, often using flagella for movement. These bacteria are capable of dissimilatory metal reduction, meaning they can use metals as terminal electron acceptors in their metabolic processes.

Electron Transfer

One of the most notable features of Geobacter is its ability to transfer electrons to external surfaces, such as iron oxides. This process is facilitated by pili and cytochromes, which act as conductive nanowires. This capability is utilized in microbial fuel cells and has potential applications in bioremediation of contaminated environments.

Ecological Role

Geobacter species play a crucial role in the biogeochemical cycling of iron and other metals. They are often found in sediments and soils where they contribute to the reduction of iron and other metals, influencing the geochemistry of these environments.

Applications

The electron transfer capabilities of Geobacter have been harnessed in various applications:

• Bioremediation: Geobacter can reduce uranium and other heavy metals, making them less soluble and less toxic.
• Bioenergy: The ability to transfer electrons to electrodes makes Geobacter a candidate for use in microbial fuel cells, which can generate electricity from organic waste.

Species

The genus Geobacter includes several species, with Geobacter sulfurreducens being one of the most studied due to its well-characterized electron transfer mechanisms.

Related pages

• Proteobacteria
• Bioremediation
• Microbial fuel cell
• Electron transfer