Biofilms as self-shaping growing nematics

Japinder Nijjer, Changhao Li, Mrityunjay Kothari, Thomas Henzel, Qiuting Zhang, Jung Shen B. Tai, Shuang Zhou, Tal Cohen, Sulin Zhang, Jing Yan

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Active nematics are the non-equilibrium analogue of passive liquid crystals. They consist of anisotropic units that consume free energy to drive emergent behaviour. As with liquid crystal molecules in displays, ordering and dynamics in active nematics are sensitive to boundary conditions. However, unlike passive liquid crystals, active nematics have the potential to regulate their boundaries through self-generated stresses. Here we show how a three-dimensional, living nematic can actively shape itself and its boundary to regulate its internal architecture through growth-induced stresses, using bacterial biofilms confined by a hydrogel as a model system. We show that biofilms exhibit a sharp transition in shape from domes to lenses in response to changing environmental stiffness or cell–substrate friction, which is explained by a theoretical model that considers the competition between confinement and interfacial forces. The growth mode defines the progression of the boundary, which in turn determines the trajectories and spatial distribution of cell lineages. We further demonstrate that the evolving boundary and corresponding stress anisotropy define the orientational ordering of cells and the emergence of topological defects in the biofilm interior. Our findings may provide strategies for the development of programmed microbial consortia with emergent material properties.

Original languageEnglish (US)
Pages (from-to)1936-1944
Number of pages9
JournalNature Physics
Volume19
Issue number12
DOIs
StatePublished - Dec 2023

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy

Cite this