Hydrogen production from the monomeric sugars hydrolyzed from hemicellulose by Enterobacter aerogenes

Relatively large percentages of xylose with glucose, arabinose, mannose, galactose and rhamnose constitute the hydrolysis products of hemicellulose. In this paper, hydrogen production performance of facultative anaerobe (Enterobacter aerogenes) has been investigated from these different monomeric sugars except glucose. It was shown that the stereoisomers of mannose and galactose were more effective for hydrogen production than those of xylose and arabinose. The substrate of 5g/l xylose resulted in a relative high level of hydrogen yield (73.8mmol/l), hydrogen production efficiency (2.2mol/mol) and a maximum hydrogen production rate (249ml/l/h). The hydrogen yield, hydrogen production efficiency and the maximum hydrogen production rate reached 104mmol/l, 2.35mol/mol and 290ml/l/h, respectively, on a substrate of 10g/l galactose. The hydrogen yields and the maximum hydrogen production rates increased with an increase of mannose concentrations and reached 119mmol/l and 518ml/l/h on the culture of 25g/l mannose. However, rhamnose was a relative poor carbon resource for E. aerogenes to produce hydrogen, from which the hydrogen yield and hydrogen production efficiency were about one half of that from the mannose substrate. E. aerogenes was found to be a promising strain for hydrogen production from hydrolysis products of hemicellulose.