Take brewer's yeast, add a gene from a salt marsh plant, grow it with an obscure bacterium found in a French landfill, and what have you got? A cheap, renewable way to fuel our cars, claims Christopher Voigt, a synthetic biologist at the University of California, San Francisco.
While biofuels derived from plants can theoretically be a carbon-neutral energy source, many also displace food-producing crops. Making them from cellulose – structural material abundant in crop waste and grasses – can sidestep that problem.
But efficient processes to do so are lacking. Voigt's team was looking for a way to get microbes to do the hard work, converting cellulose from crop waste or grasses into chemicals called methyl halides, which can in turn be turned into regular gasoline in a simple catalytic reaction.