Optimization and modeling of biohydrogen production by mixed bacterial cultures from raw cassava starch

The production of bio-hydrogen from raw cassava starch via a mixed-culture dark fermentation process was investigated. The production yield of H-2 was optimized by adjusting the substrate concentration and the microorganism mixture ratio. A maximum H-2 yield of 1.72 mol H-2/mol glucose was obtained with a cassava starch concentration of 10 g/L to give a 90% utilization rate. The kinetics of the substrate utilization and of the generation of both hydrogen and volatile fatty acids were also investigated. The substrate utilization follows pseudo first order reaction kinetics, whereas the production of both H-2 and the VFAs correlate with the Gompertz equation. These results show that cassava is a good candidate for the production of biohydrogen.