Biological hydrogen production using photosynthetic algae and bacteria can result in the generation of large amounts of waste biomass. This biomass can be used to produce hydrogen gas by modifying microbial fuel cell (MFC) technologies to produce hydrogen instead of electricity. By applying a small voltage (0.25 V in practice), it is possible to generate pure hydrogen gas at the cathode in this modified MFC process known as a bioelectrochemically assisted microbial reactor (BEAMR). Using the BEAMR process we have produced ~3 mol-H 2/mol-acetate. Linking this process with fermentation of sugars could produce 8-9 mol-H2/molglucose, at an energy equivalent of one mole of hydrogen. The process is not limited to sugars, as any biodegradable organic matter can be used, such as domestic wastewater and steam-exploded corn stover hydrolysates. Thus, it should be possible to link the BEAMR process with photosynthetic biohydrogen production in the form of algae, bacteria or crops, to create an overall sustainable biohydrogen process.