Enzymatic hydrogen production: Conversion of renewable resources for energy production

Using the enzymes glucose dehydrogenase (GDH) and hydrogenase, we have show n that a variety of sugars that are components of renewable resources can b e enzymatically converted to molecular hydrogen. The rates at which hydroge n was evolved paralleled the substrate specificity of GDH. The highest rate of hydrogen production measured was 97.8 mu mol/h, and the stoichiometric yield of hydrogen was 98% with 50 mM glucose as the substrate. Lactose, suc rose, cellulose, xylan, steam-exploded aspen wood, and starch also served a s substrates for hydrogen production when the corresponding enzymes were in cluded in the reaction mixture to generate the appropriate monosaccharide f or which GDH has specificity. The data obtained are discussed in the contex t of the rate-limiting steps of hydrogen production from renewable sugar an d the possible applications of enzymatic hydrogen production.