Photosynthetic hydrogen production from enzyme-hydrolyzed micro-grinded maize straws

Photosynthetic bacteria can produce hydrogen from various organic substrates in the presence of illumination energy. This study produced biohydrogen from maize straws by an enriched consortium via photo-fermentation pathway. The maize straws can be utilized by the consortium as substrate only after micro-grinding and enzyme hydrolysis pretreatments. Batch tests at 30 g/L maize straw, pH 7.0, 30 °C, illumination intensity 2000 lx yielded 9.33 mol H₂/mol glucose with illumination energy conversion rate of 13.7% and substrate-energy conversion rate of 5.3%. Equivalently, the biohydrogen productivity is about 3 mmol/g maize straw. Reaction temperature can affect hydrogen production rate but only minimally affect the delayed time. The activation energy for biohydrogen production was estimated to be 5.65 kJ/mol.