Comparative study of biological hydrogen production by pure strains and consortia of facultative and strict anaerobic bacteria

The experimental results compared the hydrogen production yield of 19 different pure strains and sludges: facultative and strict anaerobic HPB strains along with anaerobic digester sludges thermally pre-treated or not. Significant yields variations were recorded even between different strains of the same species by i.e. about 20% for three Clostridium butyricum strains. The pure Clostridium butyricum and pasteurianum strains achieved the highest yields i.e. up to 1.36 mol H2/mol glucose compared to the yields achieved by the sludges and the tested Escherichia and Citrobacter strains.