cyanobacteria

Generating biofuels from bacteria would be easier and potentially more efficient than producing it from plant matter -- if it weren't for the energy-intensive chemical reactions needed to extract the fuel from the bacteria after they've manufactured it. But the most promising sources of bacterial fuel, like cyanobacteria, are wrapped in multiple layers of protective membranes that make it difficult to get at the fatty material.

It seemed like an ordinary day in the primordial ooze, but romance was in the methane-ammonia air. An amoeba, pseudopoding along as usual, met and was enchanted by a particularly lovely photosynthetic bacterium. He took her inside his cell membrane, but instead of digesting her as he first planned, the two fused into a single organism. The bacterium gave the amoeba the new ability to absorb energy from sunlight, and their descendants became every plant in the world.