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Updated: Jul 13, 2025
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Monitoring Spatial Segregation in Surface Colonizing Microbial Populations
Published on: October 29, 2016
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Pleiotropic hubs drive bacterial surface competition through parallel changes in colony composition and expansion
Jordi van Gestel1,2,3,4,5,6, Andreas Wagner1,2,7,8, Martin Ackermann3,4
1Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland.
Plos Biology
|October 16, 2023
Summary
Bacteria rapidly evolved enhanced colony spreading on surfaces. Mutations in global regulators Bacillus subtilis lowered sporulation and boosted expansion by altering cell structure and gene expression, driving adaptation.
Area of Science:
- Microbiology
- Evolutionary Biology
- Genetics
Background:
- Bacterial surface growth is crucial for competition but poorly understood evolutionarily.
- Previous experiments showed rapid colony expansion in Bacillus subtilis under selection for spreading.
Purpose of the Study:
- To investigate the genetic and molecular mechanisms driving rapid bacterial evolution on surfaces.
- To analyze evolutionary changes in Bacillus subtilis colony development and expansion.
Main Methods:
- Evolution experiment with Bacillus subtilis under selection for colony spreading.
- Detailed analysis of colony development, including flow cytometry and gene expression profiling.
- Identification and characterization of mutations in global regulators.
Main Results:
- Bacillus subtilis colonies evolved a 2.5-fold increase in expansion rate.
- Mutations in global regulators (RicT, RNAse Y, LexA) were identified.
- These mutations exhibited pleiotropic effects, reducing sporulation and facilitating expansion via altered polysaccharide production or filamentous growth.
- Mutations induced parallel, reproducible changes in global gene expression affecting ~45% of genes.
- Regulatory activity changes during development and evolution drove gene expression parallelism.
Conclusions:
- Global regulators act as key hubs for rapid bacterial surface adaptation.
- Parallel evolution in gene expression and colony traits is mediated by coordinated regulator activity.
- Understanding these mechanisms provides insights into bacterial adaptation and evolution on surfaces.
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