Enhanced continuous biohydrogen production using dynamic membrane with conductive biofilm supporter

Area of Science:

• Biotechnology
• Environmental Science
• Biochemical Engineering

Background:

• Continuous biohydrogen production is crucial for sustainable energy.
• Dynamic membrane bioreactors (DMBRs) offer potential for efficient biohydrogen generation.
• Optimizing biofilm support materials is key to enhancing DMBR performance.

Purpose of the Study:

• To investigate the impact of a conductive biofilm supporter on continuous biohydrogen production within a DMBR.
• To compare the performance of a conductive stainless-steel mesh against a nonconductive polyester mesh in a DMBR setting.

Main Methods:

• Operated two lab-scale DMBRs, one with conductive stainless-steel mesh (DMBR II) and one with nonconductive polyester mesh (DMBR I).
• Measured hydrogen productivity and yield.
• Analyzed metabolic profiles using metabolic flux analysis.
• Characterized microbial communities using microbial analysis.

Main Results:

• DMBR II exhibited 16.8% greater average hydrogen productivity and yield compared to DMBR I.
• Improved hydrogen production correlated with a higher NADH/NAD+ ratio and lower Oxidation-reduction potential (ORP).
• Metabolic flux analysis indicated promotion of H2-producing acetogenesis and repression of competing pathways in DMBR II.
• Electroactive Clostridium sp. were identified as dominant hydrogen producers in DMBR II.

Conclusions:

• Conductive meshes effectively enhance biohydrogen production in DMBRs.
• The conductive supporter selectively promotes hydrogen-producing pathways.
• Conductive biofilm supporters represent a promising strategy for optimizing biohydrogen generation in DMBRs.