- Category: Technology
25 Oct 2013
- Published on Friday, 25 October 2013 04:25
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Bacteria, with their ability to grow, develop and sustain themselves in a variety of conditions, could be the miniature powerhouses that could drive us to a clean energy future.
Researchers at Arizona State University’s Biodesign Institute are studying certain bacteria’s ability to produce electricity by coordinating their metabolic activities.
They studied the light-sensitive green sulfur bacterium Chlorobium and found that – working in tandem with Geobacter, an anode respiring bacterium it can produce electricity when exposed to light.
“Geobacter is not light responsive on its own right because it’s not a photosynthetic organism,” explains Rosa Krajmalnik-Brown.
In contrast, Chlorobium is unable to carry out the anode form of respiration necessary for electricity production.
“But when you put these two organisms together, you get both a light response and the ability to generate current,” concluded Ms. Krajmalnik-Brown.
The electrons that Geobacter acquires from its photosynthetic partner Chlorobium can be measured and collected in the form of electricity in a microbial fuel cell.
The researchers call the resulting experimental configuration, in which light responsive bacteria such as the Chlorobium play a role in energy generation, as a microbial photoelectrochemical cell.
In an M.P.C., the Chlorobium gather light in order to fix carbon dioxide and fuel their metabolism. During dark phases, they sustain themselves by switching from photosynthesis to dark fermentation, using stored energy. Acetate is produced as a metabolic byproduct during this dark phase.
During the dark phase, this acetate also donates electrons to anode respiring Geobacter, this produces an electric current.
In addition to establishing a mechanism for light-responsive power generation in microbial fuel cells, the research also points to the possibility of similar co-culture studies on a range of energy-producing microbial interactions. – EcoSeed Staff