Related Experiment Video
Updated: Jul 9, 2026
08:52
Characterizing Electron Transport through Living Biofilms
Published on: June 1, 2018
Flow-driven structural and transcriptomic responses in syntrophic electroactive biofilms.
Mahshid Golalikhani1, Ahmed Elreedy1, Benjamin Fritz1
1Institute of Technical Microbiology, Hamburg University of Technology, Hamburg 21073, Germany.
Bioresource Technology
|July 7, 2026
Summary
Flow dynamics in bioelectrochemical systems impact biofilm structure and function. Faster flow creates denser biofilms, boosting energy recovery, while gene regulation in Shewanella oneidensis drives adaptation to shear stress.
Area of Science:
- Microbiology
- Electrochemistry
- Bioengineering
Background:
- Bioelectrochemical systems (BES) utilize electroactive biofilms for energy and resource recovery.
- Understanding the relationship between flow dynamics, biofilm architecture, and gene regulation is crucial for optimizing BES performance.
- Syntrophic communities in BES present complex interactions influencing system efficiency.
Purpose of the Study:
- To investigate the impact of defined surface flow velocities on the structure and electroactivity of Shewanella oneidensis-Geobacter sulfurreducens coculture biofilms.
- To elucidate the role of gene regulation in biofilm adaptation to hydrodynamic conditions.
- To identify key genetic contributors to community-level electrochemical performance in BES.
Main Methods:
- Cultivation of Shewanella oneidensis-Geobacter sulfurreducens coculture biofilms under controlled flow velocities (0.2 and 0.8 mm/s).
- Analysis of biofilm structure, biovolume, and porosity using 3D fluorescence in situ hybridization.
- Measurement of electrochemical performance (current densities).
- Transcriptomic analysis to identify shear-responsive genes, including investigation of bpfD deletion mutants.
Main Results:
- Higher flow velocities (0.8 mm/s) resulted in more compact biofilms with lower biovolume and porosity, leading to higher current densities.
- Flow transitions induced persistent, adaptive, gene-regulated structural and electrochemical shifts, primarily originating from S. oneidensis.
- Deletion of bpfD in S. oneidensis led to reduced current density and increased biofilm porosity, despite comparable biovolume, indicating its regulatory role.
Conclusions:
- Hydrodynamic conditions significantly influence biofilm architecture and electrochemical performance in BES.
- Shewanella oneidensis exhibits adaptive gene regulation in response to shear stress, impacting community function.
- A minor transcriptional contributor (bpfD) can govern overall community electrochemical performance, challenging the notion that dominant species solely dictate function.
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