Bread Wastage and Recycling of Waste Bread by Producing Biotechnological Products

In this study, continuous biohydrogen production from waste bread by anaerobic sludge was performed. The waste bread was first hydrolyzed by the crude enzymes which were generated by Aspergillus awamori and Aspergillus oryzae via solid-state fermentation. It was observed that 49.78 g/L glucose and 284.12 mg/L free amino nitrogen could be produced with waste bread mass ratio of 15% (w/v). The waste bread hydrolysate was then used for biohydrogen production by anaerobic sludge in a continuous stirred tank reactor (CSTR). The optimal hydrogen production rate of 7.4 L/(Ld) was achieved at chemical oxygen demand (COD) of 6000 mg/L. According to the results obtained from this study, 1 g waste bread could generate 0.332 g glucose which could be further utilized to produce 109.5 mL hydrogen. This is the first study which reports continuous biohydrogen production from waste bread by anaerobic sludge.