S121: Consolidated biohydrogen production from extruded prairie cord grass byThermoanaerobacterium sp. strain K1

Prairie cord grass (Spartina pectinata, PCG) is one of the potential feedstock for South Dakota’s bioenergy industry. In this study, batch experiments were carried out to convert dried and thermomechanically extruded PCG (≈ 850 μm) into hydrogen using thermophilic anaerobic enriched culture of bacteria. Characterization of enriched culture revealed the presence of axenic thermophilic bacterium (Thermoanaerobacterium sp. K1) producing hydrogen following dark fermentation process. The strain had a narrow temperature range for growth (55°C to 65°C) with optimum temperature being at 60°C. The pH 7 was found to be optimum for production of maximum yield of hydrogen. A maximum cumulative yield of 47.24 mL H₂/g-dry extruded PCG was achieved under optimized conditions of temperature and pH with 1.5g/100 mL of initial loading. Utilization of extruded PCG, biomass and metabolite production profiles were also compared. The results showed that cultures of Thermoanaerobacterium sp. K1 were able to convert PCG into hydrogen in one step consolidated process. This thermophilic consolidated bioprocess will likely to have an impact on ongoing multiple-step conversion processes of lignocellulosic biomass to hydrogen by providing a more efficient and economical process.