Capturing Bacteria Which Eat And Breathe Electricity

Abdelrhman Mohamed last August found himself hiking deep into the wilderness of Yellowstone National Park. The graduate student of WSU traveled with a team of scientists for hunting for life unlike thousands of tourists who trek to admire the iconic geysers and hot springs of the park every year.

 

The team found four pristine pools of hot water after a strenuous seven-mile walk through scenic, isolated paths in the Heart Lake Geyser Basin area. Into the edge of the water, they carefully left a few electrodes. They hope to coax little-known creatures out of hiding bacteria which can eat and breathe electricity.

 

The team returned after 32 days to the hot springs for collecting the submerged electrodes. Paul Hohenschuh, Distinguished Professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering, works under the supervision of Haluk Beyenal. Mohamed and postdoctoral researcher Phuc Ha analyzed the electrodes.

 

And guess what? They had succeeded in capturing their prey, heat-loving bacteria which breathe electricity through the solid carbon surface of the electrodes. In collaboration with colleagues from Montana State University, the WSU team published their research detailing the multiple bacterial communities which they found in the Journal of Power Sources.

 

Mohamed said that this was the first time such bacteria were collected in situ in an extreme environment like an alkaline hot spring. He further said that adding that temperatures in the springs ranged from about 110 to nearly 200 degrees Fahrenheit. These tiny creatures are not only of academic interest. They may even hold a key for solving some of the biggest challenges which humanity is facing like environmental pollution and sustainable energy. Such bacteria can "eat" pollution by converting toxic pollutants into less harmful substances. In this process, they can generate electricity.

 

Beyenal said that as these little creatures pass their electrons into metals or other solid surfaces, they can generate a stream of electricity which can be used for low-power applications. Most living organisms, including humans, use electrons. Electrons are tiny negatively-charged particles, in a complex chain of chemical reactions to power their bodies. Every organism requires a source of electrons and a place to dump the electrons to live. While we humans get our electrons from sugars in the food, we eat and pass them into the oxygen we breathe through our lungs. Many types of bacteria dump their electrons to outside metals or minerals, using protruding hair-like wires.

 

For collecting bacteria in such an extreme environment over 32 days, Mohamed invented a cheap and portable potentiostat. This is an electronic device which could control the electrodes submerged in the hot springs for long periods of time.

 

He said that the natural conditions which are found in geothermal features like hot springs are difficult to replicate in laboratory settings. So, they developed a new strategy to enrich heat-loving bacteria in their natural environment.

 

By: Preeti Narula

Content: https://www.sciencedaily.com/releases/2019/03/190305135259.htm