Extracellular electron uptake by Geobacter from solid donors: Biocorrosion and biohybrid systems

Area of Science:

• Microbiology
• Environmental Science
• Biotechnology

Background:

• Electroactive Geobacter species possess the unique ability to acquire electrons from various solid sources.
• This extracellular electron uptake (EEU) mechanism has significant implications in both natural environments and engineered systems.

Purpose of the Study:

• To review the ecological roles of EEU in Geobacter species.
• To examine the involvement of EEU in microbial corrosion and its applications in environmental engineering and biotechnology.
• To explore the molecular mechanisms underlying EEU in Geobacter.

Main Methods:

• Literature review of studies on Geobacter extracellular electron uptake.
• Analysis of molecular mechanisms, including direct contact and shuttle-mediated electron transfer.
• Examination of applications in bioelectrochemical systems and bioproduction.

Main Results:

• Geobacter utilizes EEU to interact with diverse electron donors like cathodes, metals, and biomass.
• EEU contributes to metal corrosion but also enables pollutant degradation and chemical bioproduction.
• Mechanisms include direct cell-surface contact and mediation by electron shuttles (e.g., H2, riboflavin) and cell debris.

Conclusions:

• Extracellular electron uptake is a fundamental process for Geobacter, impacting natural ecosystems and driving biotechnological innovation.
• Understanding EEU mechanisms is key to mitigating biocorrosion and harnessing Geobacter for sustainable applications.
• This review synthesizes current knowledge on Geobacter EEU, highlighting its broad significance.