Bacteria decipher mysterious human body

Great ideas come in small shape. In the case of Shewanella bacteria, they are micro-packed. But this microscopic bacterium can hold the key to alternative energy production, toxic waste cleanup and the most amazing thing is how the human body works.

As one of the most versatile species, Shewanella can live on the ground, deep in the ground or under water. When the environment changes, Shewanella also changes, finding new ways to breathe.

Daniel Bond, a bacteriologist at the University of Minnesota, said all creatures carry with them electrons along with food. Cells use electrons to generate energy, but eventually get rid of electron molecules. People do this by breathing in oxygen. The electrons go through oxygen molecules, cling when these molecules turn to CO ₂ , and then leave the body when we breathe. Shewanella can do this, but not in the land, where oxygen is scarce. Instead, in this environment, bacteria get rid of electrons by sticking them to nearby metal molecules.

Shewanella bacteria.(Photo: newscientist.com)

Relationship to alternative energy

In the laboratory, scientists have long known they can attach an electrode to these natural metals, effectively converting bacteria into tiny generators. The problem is that no one knows how bacteria move electrons from one place to another.

Bond said that such a feat is technically impossible. Like all cells, bacteria are surrounded by fat membranes.'It is considered a perfect insulation, preventing electrons from entering or leaving, but we know this is still happening. We just don't know how. '

Bond and his team changed that. On March 3, 2008, in the Proceedings of the National Academy of Sciences, they announced that they found a chemical compound that allowed electrons to pass through the fat membrane and help them move to the near metal. there. It turns out that magic makes it easy to transfer electrons to a simple riboflavin, known as vitamin B-12.

This research is funded by the Environmental and Renewable Energy Initiative, National Science Foundation and Cargill National Health Research Institute.

Put information into use

There are two main reasons why Bond's discovery is important. First, understanding how Shewanella bacteria move electrons can help scientists create better electrodes, designed with metabolism, which could make collecting electrons effective. become easier.

That's just a small amount of electricity. Bacteria will never operate a house or a car. But that does not mean that the amount of electricity they produce is not useful. For example, Bond points out that many cities have used many types of bacteria to break down harmful substances in wastewater treatment. If these plants can obtain power generated by Shewanella and other bacteria when they 'eat' toxic substances, the plant will have enough energy.

'We spend millions every year buying electricity so we can run pumps and pump air into wastewater plants. If you can recapture that energy, at least you are balanced. '

Dan Drell, biologist and program director at the Department of Energy, Ministry of Science, Washington, DC, offers another application for Shewanella. He said it, and the electricity-producing bacteria, could help clean up hazardous waste areas, and Bond's research could help.

Bacteria can decompose many toxic organic compounds. Bacteria can change other contaminants, such as heavy metals, into less dangerous forms by attaching electrons to them. Drell said riboflavin could be used to attract more bacteria and more electrons in places that needed it most.

'You can't decompose these metals, but you can change their chemistry. So instead of following the groundwater into the Columbia River, they lie still. '

Mechanism of action of bacteria

Bond's work is most important because it tells scientists about how cells work. Shewanella's genes were previously sequenced and riboflavin was one of the puzzle pieces that appeared in the chain. By figuring out the role of riboflavin, Bond put this piece in place.

Drell said 'Genetic sequence data is just data. Data that makes sense to someone becomes information and has greater value. '

How big is the value? Drell said this information is the first basement stone to understand how simple bacterial cells work, which could be a launch pad to re-understand more complex cells in the body.

'The more we understand Shewanella cells and how they work together to explain the observed behaviors, the closer we are to the basic unit of this planet, ie cell. If you solve a cell you go a long way to solve other cells. Ultimately, this also helps us understand how our own bodies work. '