in this study, the predominant H(2)-producing bacterial strain was isolated from a bio-reactor fed with lesser panda manure, and identified as Clostridium sp. based on 16S rDNA gene analysis. The bio-pretreatment of corn stalk was found to be most effective at ambient temperature of 25 degrees C, microbe additive of 7.5 g/kg with saccharification period of 15 days under the anaerobic condition. The maximum H(2)-production yield (176 ml H(2)/g-TS) and rate (18ml H(2)/g-TSh(-1)) were achieved at operating pH 5.5, 36 degrees C and substrate concentration of 15 g/L. The H(2) content in the biogas was 44.3-57.2% (v/v) and there was no significant methane gas observed. During the optimal period of H(2) production, the ORP values stayed in the lower level ranging from -445 mV to -455 mV. The results indicated that the effluent was composed mostly of butyric acid and acetic acid, which accounted for 70-80% of total VFAs, followed by small amounts of butanol and propionate. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.