As a new clean energy source hydrogen production development is a global goal because two main reasons, first, new fuels are needed to supplement and ultimately replace depleting hydrocarbon reserves, and second, clean fuels production can slow the impact of global warming. Moreover, H2 is regarded as a non-polluting fuel, because its combustion product is water (H2O). Furthermore, the energy value of H2 can be realized as electricity in a fuel cell which eliminates air-pollution problems associated with combustion. Heterotrophic fermentations for biohydrogen production are driven by a wide variety of microorganisms such as strict anaerobes, facultative anaerobes and aerobes kept under anoxic conditions. Hydrogen is presently seen to be an...