Saturday, November 3, 2007
Marine Photosynthetic Bacteria…Perhaps a New Green Fuel Source?
The interest in global warming and environmental degradation goes hand in hand with a search for new greener sources of fuel compared to oil. Well, we may have found one in marine bacteria. It has always been thought that algae were the only marine organism capable of using sunlight for energy, however in 2000, a team of American researchers discovered that a marine microbe contains a gene which codes for a light sensitive pigment. This pigment, named proteorhodopsin, is very similar to rhodopsin, a pigment found in the retina that allows us humans to detect different colours.
At the time of this discovery, scientists were not entirely sure what the pigment was used for, but they had a hunch that it was for photosynthesis. This was only proved last year, when a team of Swedish researchers at Kalmar University College collected some twenty samples of seawater from all over the world and mapped their genomes. Many of these bacteria had the gene present for the production of proteorhodopsin. What is so interesting about this is that they were able to concretely prove experimentally that this pigment converted solar energy into available energy for cellular functions and had successfully found and proven that a marine bacterium actually uses light for energy.
Studies conducted this year at the University of California at Berkley, have further given understanding to this amazing processes of marine bacteria. They found “that when the ability to respire oxygen is impaired, bacteria equipped with proteorhodopsin will switch to solar power to carry out vital life processes.” These researchers discovered that this pigment is facultative, and only kicks in under certain environmental conditions, like low oxygen availability. Many areas of the oceans are quite oxygen deprived, consequently this knowledge gives us some understanding about why so many marine bacteria possess such a pigment.
Enough of this intense science talk, what does this have to do with clean energy??? Well it’s always great to have solar options that have nothing to do with putting ugly panels on your roof! Just think if we could find a way to capture and maximize the energy produced by these bacteria, since for every one litre of seawater there are one billion bacteria. We could kiss our energy crisis goodbye, and at the same time help clean up our hydrocarbon polluted planet. Does it not sound like a win-win situation? So what is the next step? According to Liphardt, a researcher on the team at Berkeley, the next phase “is to optimize the amount of light that can be collected in cells enhanced with proteorhodopsin.” Identifying the most functionally efficient form of this pigment, and incorporating it into the genome of bacteria can achieve this.
Could you imagine if the world’s main energy source was produced by one of the most feared organisms? Wouldn’t that change our perception of bacteria!!!