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Updated: Jun 5, 2026
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A Microfluidic Device for Quantifying Bacterial Chemotaxis in Stable Concentration Gradients
Published on: April 19, 2010
Shewanella oneidensis MR-1 chemotaxis in a diffusion gradient chamber
Rui Li1, Jennifer M Auchtung, James M Tiedje
1Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States.
Environmental Science & Technology
|December 23, 2010
Summary
Shewanella oneidensis MR-1 cells exhibit chemotaxis, migrating towards electron acceptors like fumarate. The diffusion gradient chamber (DGC) accurately models this microbial behavior, aiding in understanding Shewanella
Area of Science:
- Microbiology
- Environmental Science
- Biophysics
Background:
- Shewanella species play crucial roles in environmental biogeochemical cycles.
- Understanding Shewanella's response to electron acceptors is key to elucidating its ecological functions.
- Microbial growth, metabolism, and transport are influenced by electron acceptor availability.
Purpose of the Study:
- To investigate the influence of electron acceptor gradients on Shewanella oneidensis MR-1 growth and chemotaxis.
- To validate the diffusion gradient chamber (DGC) as a tool for studying microbial responses to chemical gradients.
- To model and predict Shewanella's chemotactic behavior in response to fumarate and nitrate gradients.
Main Methods:
- Utilized the diffusion gradient chamber (DGC) to create controlled chemical gradients.
- Applied single gradients of fumarate and opposing gradients of fumarate and nitrate.
- Employed mathematical models to predict and analyze cellular growth and chemotaxis.
- Studied wild-type Shewanella oneidensis MR-1 and its fumarate/nitrate reductase mutants.
Main Results:
- Shewanella oneidensis MR-1 cells formed a chemotactic band migrating towards fumarate, matching model predictions.
- The measured velocity of the chemotactic band closely aligned with the predicted velocity (0.134 cm/h vs. 0.139 cm/h).
- The DGC successfully differentiated between wild-type and mutant strains based on their electron acceptor utilization capabilities.
Conclusions:
- The diffusion gradient chamber (DGC) is a validated tool for measuring and simulating Shewanella chemotaxis.
- This system aids in understanding how Shewanella responds to electron acceptor gradients, crucial for its environmental roles.
- The study provides insights into the ecological significance of Shewanella's differential response to various electron acceptors.
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