[Effect of initial substrate concentrations and pH on hydrogen production from xylose with Clostridium butyricum T4]

We studied the effect of initial pH and substrate concentrations on the conversion of xylose to hydrogen by Clostridium butyrium T4 at pH 5.0-8.5 and substrate concentrations 5-40 g/L. The cumulative hydrogen volume and the specific hydrogen production rate increased and then decreased with increasing initial pH or substrate concentrations. At initial pH 6.5 and substrate concentration 20 g/L, the cumulative hydrogen production and the specific hydrogen production rate reached the maximum value of 4.26 L/L and 18.86 mmol-H2/h g-DCW (dry cell weight).