Bioaugmentation for electricity generation from corn stover biomass using microbial fuel cells.

Area of Science:

• Bioenergy and Renewable Energy
• Microbial Electrochemistry
• Biomass Conversion

Background:

• Traditional corn stover processing for bioenergy is energy-intensive and costly.
• Microbial fuel cells (MFCs) offer a potential alternative for direct electricity generation from biomass.
• Effective microbial consortia are crucial for efficient biomass breakdown in MFCs.

Purpose of the Study:

• To investigate the direct electricity generation from corn stover using MFCs.
• To evaluate the impact of bioaugmentation with a specialized microbial consortium on MFC performance.
• To analyze microbial community dynamics during corn stover degradation in MFCs.

Main Methods:

• Development of a mixed microbial culture with high corn stover saccharification capability.
• Operation of single-chamber, air-cathode MFCs using glucose-acclimated and bioaugmented cultures.
• Analysis of microbial communities using Denaturing Gradient Gel Electrophoresis (DGGE) over 60 days.
• Comparison of power output using raw versus steam-exploded corn stover.

Main Results:

• MFCs with bioaugmented culture and corn stover achieved a maximum power density of 331 mW/m².
• Microbial communities evolved over time, with bacteria like Rhodopseudomonas palustris identified.
• Steam-exploded corn stover yielded 8% higher power output (406 mW/m²) compared to raw stover.

Conclusions:

• Direct electricity generation from corn stover in MFCs is feasible through bioaugmentation.
• Specialized microbial consortia can efficiently break down corn stover for bioenergy production.
• Optimized biomass pretreatment, such as steam explosion, can further enhance MFC performance.