INDISIM, an individual-based discrete simulation model to study bacterial cultures

Area of Science:

• Microbiology
• Computational Biology
• Biophysics

Background:

• Bacterial colony dynamics are complex, influenced by individual cell behavior and environmental factors.
• Understanding these dynamics requires models that capture both microscopic and macroscopic properties.
• Existing models may not fully account for the stochastic nature of individual bacterial actions.

Purpose of the Study:

• To develop and validate INDISIM, an individual-based simulation model for bacterial colonies.
• To investigate bacterial growth, behavior, and metabolic processes using INDISIM.
• To explore the relationship between individual bacterial properties and overall colony behavior.

Main Methods:

• Developed INDISIM, a discrete-time, discrete-space simulation tool.
• Modeled individual bacterial cells with stochastic, time-dependent variables (position, biomass, cell cycle).
• Incorporated a physical lattice with spatial cells containing nutrient and product concentrations.

Main Results:

• Simulated biomass distributions within bacterial colonies.
• Quantified the relationship between colony growth rate, nutrient concentration, and temperature.
• Observed metabolic oscillations in batch bacterial cultures.
• Achieved strong qualitative agreement between simulation outcomes and experimental data.

Conclusions:

• INDISIM effectively simulates bacterial colony behavior, linking individual cell properties to global colony dynamics.
• The model provides valuable insights into microbial growth, nutrient utilization, and metabolic regulation.
• Stochastic, individual-based modeling is a powerful approach for studying complex biological systems like bacterial colonies.