A bioreactor apparatus in which a container has sidewalls, a floor and a ceiling defining a chamber that contains a slurry of water, nutrients and photosynthetic microorganisms. A plurality of optical fibers, each of which has a first end disposed outside the chamber and a second end in the mixture. A light collector spaced from the container has light incident on it and focuses the light onto the first ends of the plurality of optical fibers, thereby permitting the light to be conveyed into the mixture to promote photosynthesis. At least one nozzle is in fluid communication with a source of gas, such as exhaust gas from a fossil-fuel burning power plant containing carbon dioxide. The nozzle is disposed in the mixture beneath the second ends of the optical fibers for injecting the gas into the mixture.