Electricity generation from polyalcohols in single-chamber microbial fuel cells

Area of Science:

• Biotechnology
• Renewable Energy
• Environmental Science

Background:

• Microbial fuel cells (MFCs) offer a sustainable route for bioelectricity generation.
• Lignocellulosic carbohydrates are abundant, renewable biomass resources.
• Exploring novel carbon sources for MFCs is crucial for advancing bioenergy technologies.

Purpose of the Study:

• To investigate the potential of six polyalcohols derived from lignocellulosic carbohydrates as direct carbon sources for electricity generation in mediator-less MFCs.
• To evaluate the performance of MFCs fueled by different polyalcohols in terms of power density, current density, and voltage output.
• To assess the microbial community shifts in anode biofilms in response to different polyalcohol substrates.

Main Methods:

• Cultivation of bacterial consortia enriched on acetate.
• Adaptation of microbial cultures to pentitols (xylitol, arabitol, ribitol) and hexitols (galactitol, mannitol, sorbitol).
• Performance evaluation in single-chamber, mediator-less MFCs measuring power density, current density, and voltage.
• Chemical oxygen demand (COD) removal analysis.
• Microbial community profiling using Denaturing Gradient Gel Electrophoresis (DGGE) of 16S rRNA gene fragments.

Main Results:

• Direct electricity generation was achieved from all tested polyalcohols.
• Maximum power density ranged from 1490±160 mW/m² to 2650±10 mW/m², with galactitol showing the highest output.
• Chemical oxygen demand removal exceeded 91% for most polyalcohols, except sorbitol (71%).
• Substrate type significantly influenced the composition of anode microbial communities.

Conclusions:

• Polyols derived from lignocellulosic biomass are viable substrates for electricity generation in MFCs.
• Galactitol demonstrates superior performance as a carbon source for bioelectricity production in this MFC configuration.
• The study highlights the potential of utilizing underutilized biomass resources for sustainable energy generation and microbial community dynamics are substrate-dependent.