Biological hydrogen production from nitrogen-deficient substrates

Dark fermentation of biomass using mixed bacterial cultures is one approach to producing renewable H(2). The objective of this work was to determine if this approach could be applied to N-deficient feedstocks using an N(2)-fixing mixed culture. A mixed culture produced up to 240 mL H(2)/g glucose (1.9 mol H(2)/mol glucose) from a medium initially lacking combined N. Yields from sugarcane were also promising: 170 mL H(2)/g volatile solids (7.5 mmol H(2)/g volatile solids). This approach could reduce economic and environmental costs of fermentative H(2) production, provide combined N for subsequent bioconversion stages, and improve effluent suitability for subsequent uses.