Diffusion-Limited Growth of Microbial Colonies.
Hayden Tronnolone1, Alexander Tam2, Zoltán Szenczi3
1School of Mathematical Sciences, University of Adelaide, Adelaide, SA, 5005, Australia. hayden.tronnolone@adelaide.edu.au.
Scientific Reports
|April 18, 2018
Summary
Diffusion-limited growth (DLG) in microbial colonies is studied. Bacillus subtilis shows DLG, while Saccharomyces cerevisiae
Area of Science:
- Microbial Ecology
- Mathematical Biology
- Biophysics
Background:
- Microbial colony morphology is influenced by nutrient availability and growth modes.
- Diffusion-limited growth (DLG) occurs when nutrient supply restricts colony expansion.
- Distinguishing DLG from other growth patterns is crucial for understanding microbial development.
Purpose of the Study:
- To investigate the emergence and characteristics of diffusion-limited growth (DLG) in microbial colonies.
- To differentiate DLG from other colony morphologies, such as pseudohyphal growth.
- To determine which microbial species, Bacillus subtilis and Saccharomyces cerevisiae, exhibit DLG.
Main Methods:
- Developed an agent-based model simulating microbial cells and nutrient diffusion.
- Employed a continuous reaction-diffusion model to define the parameter space for DLG.
- Conducted comparative experiments using Bacillus subtilis and Saccharomyces cerevisiae colonies.
Main Results:
- Growth directed towards a nutrient source indicates DLG influence on colony morphology.
- Bacillus subtilis exhibits DLG, consistent with model predictions.
- Saccharomyces cerevisiae does not exhibit DLG; its non-uniform growth is attributed to pseudohyphal growth.
Conclusions:
- DLG is a significant factor shaping Bacillus subtilis colony morphology.
- Saccharomyces cerevisiae's non-uniform growth is primarily driven by pseudohyphal development, not nutrient limitation.
- The study provides a framework for identifying and distinguishing DLG in microbial systems.
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