optimization of microbial hydrogen production from maize stalk using an isolated strain

Experimental designs were applied for optimizing media and process parameters for hydrogen production from maize stalk hydrolyzate by a newly isolated facultative strain. plackett-burman design was used to identify the significant components and using this method the media components - glucose, yeast extract, malt extract, peptone, and nacl were identified as significant variables influencing the production of hydrogen. the concentrations of these components were optimized using central composite design (ccd) and were found to be: glucose, 19.25g/l; peptone, 5.64g/l; malt extract, 1.64g/l; yeast extract, 3.16g/l and nacl, 4.312g/l. for further maximizing the production of hydrogen, the process parameters including ph, temperature and fermentation time were optimized by adopting box-behnken design. a maximum hydrogen yield of 0.91 mol h2/mol substrate was achieved under the optimum conditions of ph, 7.0; temperature, 34.5oc and fermentation time, 42.5h.