I recently heard of a successful effort that harvests energy from soil at plants' bases due to apparently bacterial breakdown of wastes from the plants:
Via photosynthesis a plant produces organic matter. Part of this organic matter is used for plant-growth, but a large part can’t be used by the plant and is excreted into the soil via the roots. Around the roots naturally occurring micro-organisms break down the organic compounds to gain energy from. In this process, electrons are released as a waste product. By providing an electrode for the micro-organisms to donate their electrons to, the electrons can be harvested as electricity. Research has shown that plant-growth isn’t compromised by harvesting electricity, so plants keep on growing while electricity is concurrently produced.
The PlantPower concept is based on the cooperation of plants and microorganisms to produce in-situ electricity. Plants take up carbon dioxide and water and capture light energy. This energy is stored in the chemical bonds of sugars produced, using carbon dioxide and water. Part of this chemically stored energy is transferred to the roots of the plants. This energy present in the root zone can then be captured by the so-called electro-chemical active bacteria. These organisms are capable to oxidize the organic matter present in the root zone and transfer the energy rich electrons to an electrode. The energy carried by the electrons can be used as electrical energy, after which the electrons react at another electrode with oxygen to form water.
I would like to understand this process as far as what bacteria or "micro organism(s)" are being leveraged here. It seems that they are supplementing the soil with some kind of bacteria that acts in this specific way of releasing additional electrons that can then be harvested.
Any idea as to what kind of micro organisms or bacteria have this kind of reaction wherein they release or excrete harvestable energy (and apparently CO2 + H+) upon consumption of plant "excretions" (C6H12O6)?
After doing a bit more digging, I have found some, perhaps, interesting information from Wikipedia:
What ultimately confuses me here is that the other method noted earlier does not really emphasize any particular kind of plant and therefore I can't help but think that perhaps there are some other more useful bacteria for this scenario...