Biogeochemical cycling, redox transformations and microbial actors in electrified sediment ecosystems.

In 2010 a perplexing discovery was made: marine microbes are generating electrical currents within the seafloor that extend over centimeter scale distances. Long filamentous microbes, called "cable bacteria", transport electrons from cell to cell along a chain of more than 10.000 cells. Dense populations of these cable bacteria make the seafloor operate like an electrical battery. This newly discovered process of long-distance microbial electricity is fundamentally different from neural conduction or other known conduction mechanisms in biology, and equips the cable bacteria with a competitive advantage for survival in the seafloor. Recent data on microbial diversity and activity in sediments with long-distance electron transport suggest that other microbial actors are involved and that other electron donors are used beside free sulfide. Hence, the basic hypothesis of this FWO project is that long-distance electron transport has a far stronger impact on the biogeochemical cycling and microbial ecology of natural sediment ecosystems than currently thought. Long-distance electron transport can drive redox transformations other than aerobic sulfide oxidation, and may involve players other than cable bacteria.

Keywords:BIOGEOCHEMISTRY

Disciplines:Marine ecology, Bacteriology