The pursuit of renewable sources of energy just hit a crucial breakthrough. Since the stores of fossil fuel are diminishing as we speak, researchers are trying to exploit the machinery of microorganisms for the production of diverse chemical compounds, which can be consumed by themselves or later channeled into some form of combustible fuel. One major group of those compounds are alkanes, those saturated organic compounds abundantly found in gasolline.
The study started off when ten out of the eleven strains of Cyanobacteria, that were photoautotrophically cultured, produced forms of alkanes, mostly those with 15 & 17 carbons atoms “termed penatdecane and heptadecane respectively”. Logically, that indicates that the ‘alkane-producing gene’ is shared in all ten of them, yet absent in that unlucky 11th strain. So the search was launched.
Trying to pinpoint the gene responsible for the production of alkanes through using a method referred to as subtractive genome analysis, the study authors compared ten genomes of the alkane-producing strains to figure out which genes they have in common. Next, any of those shared genes was immediately eliminated if it had additionally showed up in the genome of the NON-alkane producing strain. Eventually, the researchers were left with 17 genes found in common and the function of 10 of them had already been previously assigned. Through careful scrutiny of the families to which proteins of those remaining 7 genes probably belong to, two of them particularly stood out, being likely participants in the pathway of the alkane synthesis.
And as always, there is no better way to test the hypothesis than to consult a microbiologist’s favorite lab microbe. To our pleasant surprise, extracts from the colonies of Escherichia coli engineered to express both genes did in fact contain alkanes. So, although we are still not fully aboard the track heading the way towards large scale production of alkanes using such microbes, this is definitely a gigantic leap in the right direction!