Cell morphology drives spatial patterning in microbial communities

Proc Natl Acad Sci U S A. 2017 Jan 17;114(3):E280-E286. doi: 10.1073/pnas.1613007114. Epub 2016 Dec 30.

Abstract

The clearest phenotypic characteristic of microbial cells is their shape, but we do not understand how cell shape affects the dense communities, known as biofilms, where many microbes live. Here, we use individual-based modeling to systematically vary cell shape and study its impact in simulated communities. We compete cells with different cell morphologies under a range of conditions and ask how shape affects the patterning and evolutionary fitness of cells within a community. Our models predict that cell shape will strongly influence the fate of a cell lineage: we describe a mechanism through which coccal (round) cells rise to the upper surface of a community, leading to a strong spatial structuring that can be critical for fitness. We test our predictions experimentally using strains of Escherichia coli that grow at a similar rate but differ in cell shape due to single amino acid changes in the actin homolog MreB. As predicted by our model, cell types strongly sort by shape, with round cells at the top of the colony and rod cells dominating the basal surface and edges. Our work suggests that cell morphology has a strong impact within microbial communities and may offer new ways to engineer the structure of synthetic communities.

Keywords: biofilms; biophysics; cell morphology; self-organization; synthetic biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioengineering
  • Biofilms
  • Biophysical Phenomena
  • Computer Simulation
  • Escherichia coli / cytology*
  • Escherichia coli / genetics
  • Escherichia coli / growth & development
  • Escherichia coli Proteins / genetics
  • Microbial Consortia* / genetics
  • Microbial Consortia* / physiology
  • Models, Biological*
  • Mutation
  • Phenotype
  • Synthetic Biology

Substances

  • Escherichia coli Proteins
  • MreB protein, E coli