Characterization of a hydrogen-producing bacterium Clostridium sp. 5A-1

Fermentative hydrogen production is considered as a promising source of renewable energy, and bacterial strain is an essential factor influencing hydrogen production. In this study, a high hydrogen-producing fermentative strain was isolated from a sugar plant, and identified as Clostridium sp. 5A-1 by 16S rRNA analysis. Strain 5A-1 was found to be a robust hydrogen-producing fermentative bacterium, which could produce hydrogen under a wide range of temperature (25 degrees C-50 degrees C) and initial pH (pH 5-9). The optimum culture temperature and initial pH for hydrogen production was 43 degrees C and pH 7.5, respectively. The glucose concentration of 10 g/L resulted in the highest hydrogen production (1847 mL/L) and hydrogen production rate (231 mL/L.h), and 7 g/L glucose was the optimum substrate concentration for hydrogen yield (1.92 mol/mol glucose). Thus, Clostridium sp. 5A-1 is a potential candidate for fermentative hydrogen production.