Selection for toxin production in spatially structured environments increases with growth rate

Area of Science:

• Microbiology
• Systems Biology
• Evolutionary Biology

Background:

• Microbes compete for resources using strategies like toxin production.
• Spatially structured environments and higher growth rates are theorized to enhance the benefits of toxin production due to localized interactions.
• Previous models lacked the ability to integrate signaling and toxin production dynamics.

Purpose of the Study:

• To investigate the impact of microbial growth rate on the selection for costly toxin production.
• To test the hypothesis that toxin production is more beneficial in rapidly growing, spatially structured environments.
• To expand the capabilities of dynamic flux balance analysis for microbial ecosystem modeling.

Main Methods:

• Developed a genome-scale metabolic modeling approach.
• Utilized the dynamic flux balance analysis platform, Computation Of Microbial Ecosystems in Time and Space (COMETS).
• Integrated signaling and toxin production into the COMETS framework.
• Performed comparative genomics analyses across diverse microbial species.

Main Results:

• The modeling framework predicts that increased growth rate strengthens the selection for toxin production.
• Comparative genomics data support the model's prediction.
• Toxin production is more likely to be maintained in fast-growing, spatially structured microbial communities.

Conclusions:

• Microbial growth rate significantly influences the selective advantage of toxin production.
• Rapidly growing, spatially structured microbial communities are key environments for maintaining toxin production.
• Findings improve the management of microbial communities and guide natural product discovery.