Seaweed would seem to an ideal source of biomass for making renewable fuels. Kelp has a high sugar content; it doesn’t need farmland or fresh water and large quantities can be sustainably harvested. Harvesting the kelp which is already growing along 3% of the world’s coastlines could potentially produce 60 billion gallons of ethanol.

The problem with kelp is that its primary sugar, alginate, could not be broken down efficiently enough to produce biofuel on an industrial scale.

Now, scientists from the Bio Architecture Laboratory in Berkeley, California, have genetically engineered a strain of E. coli bacteria capable of digesting kelp sugars into more accessible glucose. The microbial components can then be rearranged to produce different types of fuel, including butanol, which can blended into gasoline, or biodiesel,

The process now needs to be refined to be econically viable before it can be scaled-up for industrial use.