Screening sediment samples used as anolytes in microbial fuel cells for microbial electron transfer activity using...

Area of Science:

• Microbiology
• Electrochemistry
• Environmental Science

Background:

• Microbial fuel cells (MFCs) rely on microbial electron transfer for energy generation.
• Screening potential anolytes is crucial for optimizing MFC performance.
• Existing methods for assessing electron transfer activity can be time-consuming.

Purpose of the Study:

• To evaluate the dye reduction-based electron-transfer activity monitoring (DREAM) assay for screening anolyte samples.
• To determine the correlation between DREAM assay results and MFC performance.
• To identify optimal anolyte materials for MFCs.

Main Methods:

• The DREAM assay was used to measure microbial electron transfer activity.
• Redox dyes (methylene blue, resazurin) were employed to quantify electron transfer.
• DREAM assay coefficients were compared with power density generated in MFCs.
• Chemical oxygen demand (COD) was also analyzed.

Main Results:

• The DREAM assay effectively measured electron transfer activity, indicated by dye reduction.
• DREAM assay coefficients showed strong positive correlations with MFC power density (r=0.976) and COD (r=0.934).
• Activated sludge demonstrated the highest DREAM coefficient and power density.

Conclusions:

• The DREAM assay is a rapid, sensitive, and cost-effective method for evaluating microbial electron transfer activity.
• It is suitable for screening inocula used as anolytes in MFCs.
• The assay provides reliable data comparable to MFC performance.