Shewanella

Definition

Shewanella is a genus of gram-negative bacteria known for its ability to reduce metals and other compounds, which plays a significant role in biogeochemical cycling. These bacteria are often found in aquatic environments and have gained attention for their potential applications in bioremediation, bioenergy, and microbial fuel cells due to their unique electron transfer capabilities.

5 Must Know Facts For Your Next Test

1. Shewanella species can utilize a wide variety of electron acceptors, including iron, manganese, and sulfate, which allows them to thrive in diverse environments.
2. These bacteria are capable of reducing heavy metals like uranium and chromium, making them valuable for environmental cleanup efforts.
3. Shewanella is also known for its metabolic flexibility, as it can switch between aerobic and anaerobic respiration depending on the availability of oxygen and electron acceptors.
4. Some species of Shewanella produce conductive biofilms that can enhance electron transfer rates in microbial fuel cells, improving energy production efficiency.
5. Research on Shewanella has led to the discovery of unique proteins involved in electron transport, opening new avenues for biotechnology applications.

Review Questions

• How do Shewanella bacteria contribute to biogeochemical cycling in aquatic environments?
  • Shewanella bacteria play a crucial role in biogeochemical cycling by reducing various compounds, including metals, which facilitates nutrient cycling in aquatic ecosystems. Their ability to utilize different electron acceptors allows them to participate in processes such as iron and manganese cycling. This contributes to the overall health of aquatic environments and helps maintain the balance of nutrients essential for other organisms.
• Discuss the significance of Shewanella in bioremediation and how it can be applied to environmental cleanup.
  • Shewanella species are significant in bioremediation due to their capability to reduce heavy metals and other contaminants. They can convert toxic forms of metals like chromium and uranium into less harmful forms, thus aiding in the detoxification of polluted environments. By utilizing these bacteria in bioremediation strategies, we can enhance the efficiency of environmental cleanup efforts and restore contaminated sites more effectively.
• Evaluate the potential applications of Shewanella in bioenergy production and how its unique characteristics contribute to this field.
  • The potential applications of Shewanella in bioenergy production are promising due to its ability to transfer electrons efficiently through conductive biofilms. This characteristic makes Shewanella an ideal candidate for use in microbial fuel cells, where it can convert organic matter into electricity. Additionally, understanding its unique electron transport mechanisms can lead to innovations in energy production technologies, emphasizing the importance of these bacteria in sustainable energy solutions.

Related terms

Bioremediation: A process that uses microorganisms to remove or neutralize contaminants from soil and water.

Electrogenic Bacteria: Bacteria capable of transferring electrons to electrodes, which can be harnessed for bioenergy applications.

Geobacter:

A genus of bacteria similar to Shewanella, known for its ability to transfer electrons to metals and electrodes, playing a significant role in biogeochemical processes.