Combined influence of hydrodynamics and chemotaxis in the distribution of microorganisms around spherical nutrient sources

Authored by Nikhil Desai, Arezoo M Ardekani

Date Published: 2018

DOI: 10.1103/physreve.98.012419

Sponsors: United States National Science Foundation (NSF)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

We study how the interaction between hydrodynamics and chemotaxis affects the colonization of nutrient sources by microorganisms. We use an individual-based model and perform probabilistic simulations to ascertain the impact of important environmental and motility characteristics on the spatial distribution of microorganisms around a spherical nutrient source. In general, we unveil four distinct regimes based on the distribution of the microorganisms: (i) strong surface colonization, (ii) rotary-diffusion-induced ``off-surface{''} accumulation, (iii) a depletion zone in the spatial distribution, and (iv) no appreciable aggregation, with their occurrence being contingent on the relative strengths of hydrodynamic and chemotactic effects. More specifically, we show that the extent of surface colonization first increases, then reaches a plateau, and finally decreases as the nutrient availability is increased. We also show that surface colonization reduces monotonically as the mean run length of the chemotactic microorganisms increases. Our study provides insight into the interplay of two important mechanisms governing microorganism behavior near nutrient sources, isolates each of their effects, and thus offers greater predictability of this nontrivial phenomenon.
Tags
Model Bacterial chemotaxis Mechanisms Escherichia-coli Motion Biofilm formation Interface Particle Predictions Marine microorganisms Biofilm formation Balance equation Droplet breakup Oil releases Motile algae Hard-wall Droplet breakup