Thermophilic Hydrogen Production from Renewable Resources: Current Status and Future Perspectives

Hydrogen (H-2) is considered an alternative fuel of the future due to its high energy density and non-polluting nature. H-2 energy provides many advantages over fossil fuels in that it is renewable, eco-friendly, and efficient. The global demand for H-2 is increasing significantly; however, matching the supply of cost-competitive H-2 to meet the current demand is a major technological barrier. H-2 can be produced from lignocellulosic biomass and serve as a raw material for the synthesis of many industrially important chemicals. The use of thermophilic bacteria for biological production of H-2 appears to be a promising alternative route to the current H-2 production technologies. However, the carbon and H-2 production metabolisms in most thermophilic bacteria have not yet been completely understood. This paper summarizes the recent research progress made toward understanding the carbon utilization for H-2 production and developing gene manipulation techniques to enhance the H-2 production capabilities in thermophilic bacteria. It reviews the current status, future directions and opportunities that thermophiles can offer to enable a cost-competitive and environmentally benign H-2 production bioprocess.