It’s hard to think of a humbler organism than algae, or a less-likely prospect to become savior of our energy future. “Algae fuel” does not conjure up images of power, big business or high-tech gadgetry; it suggests a modest picture of a murky pond covered by a greasy, greenish film. But unassuming algae, some researchers think, have the potential to become the ultimate in “green” fuel, powering everything from cars to jets — and perhaps putting an end to one of the more bitter battles in the biofuels industry: the “food versus fuel” debate over how best to use arable lands.