Cyanotheces 51142

When Craig Venter made synthetic life earlier this year, he gave possible future applications of synthetic biology. High on the list of near-term applications, he mentioned designing microbes that use sunlight to produce hydrogen. Well, nature has beaten him to it. Sort of.

These handsome things belong to a species of cyanobacteria (blue-green algae) called Cyanothece 51142. By day, they make glucose with carbon dioxide and sunlight, like most plants. But by night, an enzyme uses the glucose plus nitrogen in the air to produce ammonia, which gives off hydrogen as a by-product.

What we have on our hands is a bacterium that makes hydrogen using energy from sunlight. This is significant because hydrogen is likely to serve a major supporting, if not leading role in our future energy economy.

The idea goes like this. Energy is very difficult to store in any great magnitude for a prolonged period of time. Renewable energy sources like solar power and wind power are intermittent, so a long-term means of storing huge amounts of energy is necessary. Hydrogen gas can be created in endothermic (energy-consuming) reactions, and can later be combined with oxygen in a fuel cell to give energy and water.

There are no natural sources of hydrogen gas, so a big problem with this concept is the present lack of an efficient means to make hydrogen. The amount of energy you put in to create the hydrogen vastly outweighs the amount you get back at the end. If we could bring the values closer to parity, it would go along way to making a hydrogen economy feasible.

By genetically tweaking organisms like Cyanotheces 51142, we might gain an efficient way of using the energy of sunlight to produce hydrogen.

Of course, there are other problems with a hydrogen economy. There are concerns over hydrogen's energy density, our ability to store it safely, and our ability to make efficient fuel cells to recombine the hydrogen at the end of the process.

But nonetheless, the discovery of this little critter can only be good news.