Electron Transfer in the Biogeochemical Sulfur Cycle

Area of Science:

• Microbiology
• Biogeochemistry
• Environmental Science

Background:

• Microorganisms are central to the global sulfur cycle.
• Electroactive microbes perform extracellular electron transfer, crucial for ecological processes.
• Diverse phylogenetic and metabolic capabilities are observed in these microbes.

Purpose of the Study:

• To review electron transfer mechanisms in electroactive microorganisms within the sulfur cycle.
• To explore long-distance electron transfer and extracellular electron transfer phenomena.
• To discuss the role of pili/cytochrome and novel study approaches for electroactive microbes.

Main Methods:

• Literature review of microbial electron transfer processes.
• Analysis of syntrophic interactions between bacteria and archaea.
• Examination of electron transfer in multicellular filamentous bacteria.

Main Results:

• Sulfate-reducing bacteria and anaerobic alkane-oxidizing archaea engage in syntrophic electron transfer.
• Multicellular filamentous sulfur-oxidizing bacteria exhibit long-distance and extracellular electron transfer.
• Pili and cytochromes are key mediators of microbial electron transfer.

Conclusions:

• Electroactive microorganisms are vital for the biogeochemical sulfur cycle.
• Understanding their electron transfer mechanisms offers insights into microbial sulfur metabolism.
• Applications in sustainable bioelectronics and bioremediation are significant.