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Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat
Published on: September 20, 2016
Microbial evolution in a simple unstructured environment: genetic differentiation in Escherichia coli
R F Rosenzweig1, R R Sharp, D S Treves
1Department of Biology, University of Michigan, Ann Arbor 48109.
Genetics
|August 1, 1994
Summary
Escherichia coli populations evolved stable resource partitioning between acetate and glycerol, leading to polymorphism. This demonstrates how resource specialization can drive incipient speciation in asexual microbes.
Area of Science:
- Microbial Evolution
- Population Genetics
- Biochemistry
Background:
- Long-term cultures of single-clone Escherichia coli populations under glucose limitation develop polymorphism.
- Stable coexistence of different clones within a population indicates complex ecological and genetic interactions.
Purpose of the Study:
- To investigate the mechanisms maintaining stable polymorphism in Escherichia coli populations.
- To understand the role of resource partitioning in microbial evolution and speciation.
Main Methods:
- Isolation and characterization of distinct clones from a polymorphic population.
- Reconstruction experiments to assess clone stability and interactions.
- Analysis of metabolic pathways for acetate and glycerol utilization and production.
Main Results:
- Three distinct clones were maintained in stable polymorphism, despite differences in growth rates and glucose uptake.
- Differential secretion and uptake of acetate and glycerol explained the stable coexistence.
- Mutations in acetyl-coenzyme A synthetase and glycerol regulon/kinase affected metabolite handling.
Conclusions:
- Resource partitioning, driven by mutations affecting acetate and glycerol metabolism, promotes stable polymorphism in Escherichia coli.
- This evolutionary process may represent an early stage of speciation in asexually reproducing organisms.
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