Electric Ecology
In just one teaspoon of mud, the researchers found a full half-mile of Desulfobulbaceae cable, and it's not just a Danish phenomenon. Nielsen said other researchers have sent him samples from seafloors around the world, including Tokyo Bay. It's possible that, at the microbial level, the deep seafloor is humming with current.
With so much electricity being transferred, are other organisms tapping the lines? Might the Desulfobulbaceae be a power source for entire as-yet-unappreciated deep-sea microbial ecologies, which in turn shape some of the planet's fundamental biogeochemical processes? That's "an interesting possibility," said Nielsen, but it's still speculation.
Less speculatively, the Desulfobulbaceae are definitely breaking down iron sulfides and carbonates in deeper sediment, while generating iron oxide and magnesium calcite at the surface, Nielsen said. The latter are important compounds for life in the oceans above, and ultimately on land. If the new Desulfobulbaceae are as widespread and populous as they seem, they could be an important component of life's deep-time cycles.
Image: Nils Risgaard-Petersen