Shaping the Growth Behaviour of Biofilms Initiated from Bacterial Aggregates

TL;DR

This study uses agent-based simulations to explore how the initial shape of bacterial aggregates influences biofilm growth, revealing that spreading or rounding impacts success depending on competition levels.

Contribution

It introduces the role of initial aggregate shape in biofilm development and highlights the trade-off between surface area and height affecting biofilm success.

Findings

Spread aggregates perform better with low competition.

Rounded aggregates perform better with high competition.

Initial shape influences biofilm development outcomes.

Abstract

Bacterial biofilms are usually assumed to originate from individual cells deposited on a surface. However, many biofilm-forming bacteria tend to aggregate in the planktonic phase so that it is possible that many natural and infectious biofilms originate wholly or partially from pre-formed cell aggregates. Here, we use agent-based computer simulations to investigate the role of pre-formed aggregates in biofilm development. Focusing on the initial shape the aggregate forms on the surface, we find that the degree of spreading of an aggregate on a surface can play an important role in determining its eventual fate during biofilm development. Specifically, initially spread aggregates perform better when competition with surrounding unaggregated bacterial cells is low, while initially rounded aggregates perform better when competition with surrounding unaggregated cells is high. These contrasting outcomes are governed by a trade-off between aggregate surface area and height. Our results provide new insight into biofilm formation and development, and reveal new factors that may be at play in the social evolution of biofilm communities.