Optimization of media composition for the production of biohydrogen from waste glycerol

Enterobacter aerogenes has a known ability to convert glycerol during a fermentative process to yield hydrogen and ethanol as the main products. A Box-Behnken design and response surface methodology were used to determine the optimal concentration of some media constituents and oxygen to maximize the yield of biohydrogen. Results indicated that the concentration of the salts studied: NH4NO3, FeSO4, and Na2HPO4 and; the presence of oxygen in the pre-culture significantly influence the production of biohydrogen. Optimal conditions were determined to be 7.5% O2 in the inoculum transfer step, ratio of inocula 18%, 8 g/L of Na2HPO4, 0.00625 g/L of FeSO4 and 1.5 g/L of NH4NO3