Genetic engineering allowed human kind to evolve and differentiate certain species of food, make them better or more productive. Likewise, genetic engineering is blamed to have ruined the natural evolution path of the affected plants or animals. Now, genetic engineering is being used to extract energy for us, in the form of hydrogen.
Erwin Reisner and Fraser Armstrong, from the Oxford University in the UK, have discovered a type of bacteria that can convert water into hydrogen in the relative absence of oxygen. It uses some enzymes converting hydrogen ions into hydrogen gas. The process is called “hydrogenase”.
Until now, hydrogenase has been hard to get because of the high air quality conditions it has to have (as in: no oxygen, not even 1%). Minute quantities of oxygen would have crippled the bacteria’s enzymes. But Erwin and Armstrong’s bacteria is resistant to both hydrogen and oxygen, continuing to work even if the surrounding air has 1% oxygen by volume. In past experiments, even a few parts per million would have blocked the hydrogenase.
The dust particles are each attached both to the enzyme and to light-absorbing dye molecules that are used in some solar cells.
In the presence of an electron-donating buffer solution, the dye absorbs light and releases excited electrons, which then pass to the enzyme. Suitably energised, the hydrogenase then converts hydrogen ions from water molecules into hydrogen gas – just as they would during the bacteria’s respiration.
In a first trial, a small sample of the nanoparticles spent 8 hours in a solution under a tungsten-halogen lamp. The headspace gas above the solution got a 4.6% hydrogen – a “promising for a first trial”, as Armstrong says. Without the enzyme, only trace quantities of hydrogen would have been produced.
Really interesting experiment, that is sometimes able to be compared with platinum catalysts-helped hydrogen production. Not only is this method cheaper, but it is also more environmentally friendly from one point of view. The only danger that could arise would be that of an experiment got out of control. But, still, it’s interesting to comment on…