May 13, 2018 05:07 PM
Quote: A muddy picturehttps://www.sciencedaily.com/releases/20...111739.htm
The CEM basic research centre was set up in 2017 to find answers to some of the questions that mushroomed after the discovery of these living electrical cables in the seabed under the Aarhus Bugt seven years ago.
How can a living biological structure act as an efficient electrical conductor? How does the cable bacterium distribute energy between cells? And how do they use the energy? At that time, researchers literally only had a muddy picture of what was going on in these long, thin bacteria. The bacteria transport electrons from the oxygen-free mud a couple of centimetres down in the seabed to the oxygen-rich mud and silt on the surface, making it possible for them to eat with one end and breathe with the other.
... is made clearer with laser light
After having brought live cable bacteria under the microscope and exposed them to resonance Raman spectroscopy, the research group has come closer to one of the answers. Their results are published in the scientific journal PNAS on May 7th.
Raman spectroscopy illuminates molecules with laser light. The frequency distribution of the scattered light makes it possible to read the energy level of the molecules.
"In this context, we have used the instrument as an advanced voltmeter, that we have targeted towards a specific type of proteins, cytochromes, in the cables," said first author of the publication, Jesper T. Bjerg, PhD student at Aarhus University.
Power cut
The head of CEM, Professor Lars Peter Nielsen, explains.
"All living cells move electrons around and try to park them in so-called cytochromes. The more free parking spaces there are, the higher the electrical potential. With our advanced voltmeter, we have now measured the available parking spaces and thus the electrical potential of each cytochrome along the wires of individual cable bacteria, while these wires conduct electrons from one end of the bacteria to the other. Our measurements showed the lowest potential in the cells at the end where electrons from the food source were being loaded, and the highest potential at the opposite end, where the electrons were being unloaded to oxygen."
