Who wins? Analysis and Simulation of a Batch Culture Model of Bacterial Competition in the Presence of Plasmids.

Bacteria are essential in research and commercial processes for producing DNA, proteins, and converting raw materials into high-value molecules, often using batch culture systems. These systems provide controlled conditions for bacterial growth, which is influenced by factors like temperature, oxygen, and nutrients. This study introduces a mathematical model of plasmid dynamics, including loss, uptake, and transfer by conjugation, within batch cultures. The model helps optimize E. coli cultures for product formation and predict plasmid-carrying bacteria levels, offering insights into plasmid dynamics in "one-pot" systems. Our findings show that plasmid retention is influenced by selection pressures which can be an important consideration in probiotic dosing regimens. The model aligns with experimental data and highlights the importance of understanding plasmid dynamics for controlling bacterial growth processes, with implications for research, commercial applications, and gut microbiome stability. Future work will explore temporal changes in plasmid dynamics, requiring advanced instrumentation for precise bacterial population quantification.