21 October 2015
Source: New Scientist
In the depths of the ocean, the boundaries between two different domains of life, bacteria and archaea, seem to blur.
Dwelling together in seabed sediments, these microorganisms link up to form extensive power grids, ones that ultimately allows them to oxidise methane in the ocean.
The process ensures that vast stores of this greenhouse gas are not released into the atmosphere. But how this microbial partnership manages to do this in the oxygen-free conditions here has been a puzzle for decades.
Two studies, one led by Boetius, the other by Victoria Orphan at the California Institute of Technology in Pasadena, seem to have solved the puzzle. The bacteria form minuscule nanowires to connect with archaea – and this allows a mutually beneficial process to take place.
For aerobic organisms such as ourselves, food is “burned” in the presence of oxygen to generate energy. But this is not an option for the microbes living at depth, where there is no oxygen. These bacteria essentially do the same thing with sulphate instead of oxygen.