Since hydrogen is a renewable energy source, biohydrogen has been researched in recent years. However, there is little data on hydrogen fermentation by a leachate from a waste landfill as inoculum. We investigated hydrogen production using a leachate from an industrial waste landfill in Kanagawa prefecture. The results showed no methane gas production and the leachate was a suitable inoculum for hydrogen fermentation. The maximum H(2) yield was 2.67 mol of H(2) per mol of carbohydrate added, obtained at 30 degrees C and initial pH 7. The acetate and butyrate production was significant when the H(2) yield was higher. The oxidation-reduction potential analysis of the culture suggested that hydrogen-producing bacteria in the leachate were facultatively anaerobic. Scanning electron microscope observations revealed hydrogen-producing bacteria comprised bacilli of about 2 mu m in length. (C) 2009 Elsevier Ltd. All rights reserved.