Rational comparison of biohydrogen production using Clostridium species through dark fermentation during anaerobic...

Bacteria of the genus Clostridium are remarkable for their ability to produce hydrogen from a wide range of substrates through dark fermentation. This type of fermentation has been extensively studied in the literature. However, a large number of culture conditions were applied, making it difficult to compare different strains in terms of hydrogen production performance. The potential of Clostridium is therefore not fully explored. This study compared the performances of four clostridial strains in terms of hydrogen production under batch conditions, in a stirred tank with a regulated pH, at atmospheric pressure. Glucose was used as the sole carbon substrate. Clostridium pasteurianum ATCC 6013 (= DSM 525) was the strain with the highest gas volume production of 866 (± 291) mL_gas/(L_bioreactor·h). This strain is able to exhibit a hydrogen to substrate yield of 1.73 (± 0.12) mol/mol and a hydrogen to carbon dioxide ratio of 1.03 (± 0.13) mol/mol, which are values comparable to those of other strains studied. By combining every parameter, it appears that ATCC 6013 is a certain strain of interest for high-volume H₂ production.