# Biophysics of Bacterial Colonial Structures and the Occupancy of Microecological Spaces

## TL;DR

This paper explores how bacterial colonies form physical structures that impact fluid flow and ecosystems, influencing both biological and industrial systems.

## Contribution

The paper introduces a novel perspective on bacterial colonies as physical entities that transform biological processes into physical phenomena.

## Key findings

- Bacterial colonies create microcompartments and fluid channels through physical heterogeneity.
- Biofilms retain water via exopolymers and expand through lateral slippage of layers.
- Colonies affect fluid mechanics and contribute to material degradation in industrial settings.

## Abstract

Bacterial colonies constitute physical entities. Thus, beyond their biological activities, microorganisms exert effects arising from their physical occupation of microecological spaces, particularly altering the flow of fluids within macroorganisms and the environment.

The process of bacterial reproduction on surfaces conducive to growth forms colonies, which are defined as physical bodies with functional and environmental effects. This phenomenon can be conceptualized as transforming biological processes into physical phenomena. Large bacterial multicellular aggregates can be conceptualized as physical entities, produced by “colonial organisms”, thereby transforming physics into biology. The formation of colonies requires surfaces, typically hydrogels or liquid–air interfaces, but also hard solid surfaces. Bacterial cell layers also contribute to the production of surfaces. Within a typical 3D-shaped, frequently domed colony, a variety of microcompartments form at the intersections of gradients that diffuse from its aerial and surface limits, leading to cellular functional diversity. This heterogeneity can lead to physical changes and fractures in the colony material, leading to the formation of fluid microchannels. The second primary type of colony is the 2D-shaped form that spreads over larger surfaces and is known as a biofilm. These physical structures possess significant water content, which is retained by a bacterial-excreted exopolymer. Biofilms are structurally organized as multilayer structures that can expand in the space through the lateral slippage of a more fluid overlayer on top of the surface-attached layer. The dissemination of biofilms may entail the integration of additional bacterial colonies, thereby giving rise to complex biofilms. The physical occupancy of microenvironments by colonies created on surfaces of higher organisms or on environmental surfaces exerts a significant influence on fluid mechanics and the functioning of organisms and ecosystems. In addition, colonies also contribute to the pathology of industrial constructions and devices, often leading to microbiologically influenced electrochemical corrosion, which results in material degradation.