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Updated: May 22, 2026
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High-Throughput Live Imaging of Microcolonies to Measure Heterogeneity in Growth and Gene Expression
Published on: April 18, 2021
Real-time spatial gene expression analysis within current-producing biofilms.
Ashley E Franks1, Richard H Glaven, Derek R Lovley
1Department of Microbiology, University of Massachusetts, Morrill IVN, 639 North Pleasant Street, Amherst, MA, USA. aefranks@microbio.umass.edu
Chemsuschem
|May 12, 2012
Summary
Researchers developed a real-time reporter system to track gene expression in Geobacter sulfurreducens biofilms. This method reveals metabolic activity and aids in optimizing microbe-electrode technologies for better current production.
Area of Science:
- Microbiology
- Bioelectrochemistry
- Molecular Biology
Background:
- Geobacter sulfurreducens is crucial for extracellular electron transfer in microbial fuel cells.
- Understanding gene expression in anode biofilms is key to optimizing microbial electrosynthesis and current production.
- Real-time monitoring of gene activity in situ remains a challenge.
Purpose of the Study:
- To develop and validate a real-time reporter system for monitoring gene expression in Geobacter sulfurreducens anode biofilms.
- To investigate the spatial and temporal expression patterns of key metabolic and electron transfer genes.
- To assess the metabolic activity of cells throughout the biofilm, including those distant from the anode.
Main Methods:
- Engineered Geobacter sulfurreducens strains with a fluorescent protein reporter gene under the control of target gene promoters.
- Cultivation of anode biofilms in a specialized chamber for direct microscopic observation.
- Confocal scanning laser microscopy to visualize cell fluorescence and gene expression in real-time.
- Analysis of reporter gene expression dynamics in response to environmental stimuli.
Main Results:
- The reporter system accurately tracked the initiation and termination of gene transcription.
- Genes for citrate synthase, PilA (pili structural protein), and OmcZ (cytochrome) showed uniform expression across the biofilm.
- OmcZ was localized at the anode-biofilm interface, essential for current production.
- Metabolic activity was confirmed even in cells far from the anode, suggesting contributions to current generation.
Conclusions:
- The developed real-time reporter system is effective for studying gene expression in G. sulfurreducens biofilms.
- Metabolic activity is widespread in anode biofilms, with factors beyond gene expression influencing protein localization.
- This approach offers a valuable tool for advancing technologies reliant on microbe-electrode interactions, such as microbial fuel cells.
