Photosynthesis, Chemosynthesis and Now Electrosynthesis

It's an SF story come real. Japanese scientists identified microbes that survive on electric energy. There have so far been two methods known to produce nutriment from carbon, namely photosynthesis whereby sunlight synthesizes farina from carbon dioxide and chemosynthesis utilizing hydrogen, sulfur and etc. as an energy source beyond the reach of sunlight.

Now, a joint research team of the University of Tokyo and the Institute of Physical and Chemical Research has identified the existence of microbes capable of electrosynthesis and bared a part of the metabolic mechanism.

In 2010, a stepping stone was laid leading to the discovery this time. Huge deposits of highly electroconductive rocks were confirmed at the ocean far beyond the reach of sunlight. It was discovered then that the hot water gushing up out the ocean floor produces electricity with the electroconductive rocks as catalyst, which led to a hypothesis that part of organisms resident at the ocean floor might be surviving on electricity as the third source of energy.

The researchers further confirmed that when acidithiobacillus ferrooxidans (A.ferrooxidans), a kind of thiobacillus ferrooxidans which utilize ferrous ion as energy source are put in an environment without ferrous ion and electricity is the only source of energy, the cells start multiplying.

It was confirmed then that the cells produce NADH by pulling out electrons from electrodes outside and synthesize organic matters from carbon dioxide via rubisco protein.

Furthermore, it was confirmed this kind of thiobacillus ferrooxidans can uplift a nominal potential difference of 0.3V to over 1V, that is to say capable of utilizing a very feeble electric energy.

All this amounts to the fact that the cells turn the branched type transportation path spreading from exile to intima into a booster circuit to raise the voltage to 1.14V and survive on potential difference.

It is more than likely that there exists at the ocean floor an entirely new ecological system.

News Source: Gigazine