Utilization of wheat for biohydrogen production by a combination of solid-state fermentation and batch fermentation

• A novel biological strategy for hydrogen production was developed.
• Wheat bran was used in solid-state fermentation to produce enzyme solutions.
• The resulting solutions were utilized to hydrolyze wheat flour.
• The wheat flour hydrolyzate was used as feedstock for biohydrogen production.
• The highest cumulative hydrogen production of 4.52 L was obtained.

A novel biological strategy of utilizing wheat as nutrient source for hydrogen production was developed. Wheat bran was used in the solid-state fermentations of Aspergillus awamori and Aspergillus oryzae that produce amylolytic and proteolytic enzyme streams, respectively. The resulting streams were added to wheat flour to generate nutrients-rich (glucose and free amino nitrogen (FAN)) solutions. Both glucose and FAN increased with increasing of wheat flour mass ratio from 3% to 10% (w/v) and the highest glucose (43.92 g/L) and FAN (944.53 mg/L) were obtained at wheat flour mass ratio of 10%. The wheat flour hydrolyzates were then used as the feedstock for biohydrogen production by Biohydrogenbacterium R3. The highest cumulative hydrogen production of 4.52 L was happened at glucose concentration of 33.15 g/L. However, the maximum hydrogen yield (2.34 mol H2/mol glucose) and hydrogen production (0.074 L H2/g wheat flour) were obtained at glucose concentration of 16 g/L.