Improvement of hydrogen production by newly isolated Thermoanaerobacterium thermosaccharolyticum IIT BT-ST1

• Isolation of potential H2 producing thermophilic microorganism.
• Taguchi design of experiment for process assessment.
• Box–Behnken design to find out the mutual interaction of different parameters.
• Continuous hydrogen production using packed bed reactor.
• Comparative studies with the reported thermophilic cultures.

Efficient H2 producing bacterial strain Thermoanaerobacterium thermosaccharolyticum IIT BT-ST1 was isolated from the anaerobic digester. Taguchi design of experiment was applied to evaluate the influence of the temperature, pH, glucose, FeSO4 and yeast extract on H2 production with three levels of orthogonal array in the experimental design. Temperature showed most significant influence on the H2 production process. Investigation of mutual interaction between the process parameters was studied employing Box–Behnken design. Experimentally optimized process parameters (60 °C, pH 6.5, 20 mM FeSO4, 4 g L−1 yeast extract and 12 g L−1 glucose) gave the maximum H2 production of 3930 mL L−1 in 24 h, which have close resemblance with the theoretical values. Continuous H2 production using packed bed reactor was studied. Maximum H2 production rate of 1691 mL L−1 h−1 at a dilution rate of 0.6 h−1 was observed which is about 10 times higher than the batch process.