Bacterial Multicellularity: The Biology of Escherichia coli Building Large-Scale Biofilm Communities

Annu Rev Microbiol. 2021 Oct 8:75:269-290. doi: 10.1146/annurev-micro-031921-055801. Epub 2021 Aug 3.


Biofilms are a widespread multicellular form of bacterial life. The spatial structure and emergent properties of these communities depend on a polymeric extracellular matrix architecture that is orders of magnitude larger than the cells that build it. Using as a model the wrinkly macrocolony biofilms of Escherichia coli, which contain amyloid curli fibers and phosphoethanolamine (pEtN)-modified cellulose as matrix components, we summarize here the structure, building, and function of this large-scale matrix architecture. Based on different sigma and other transcription factors as well as second messengers, the underlying regulatory network reflects the fundamental trade-off between growth and survival. It controls matrix production spatially in response to long-range chemical gradients, but it also generates distinct patterns of short-range matrix heterogeneity that are crucial for tissue-like elasticity and macroscopic morphogenesis. Overall, these biofilms confer protection and a potential for homeostasis, thereby reducing maintenance energy, which makes multicellularity an emergent property of life itself.

Keywords: RpoS; bacterial second messenger; c-di-GMP; cellulose; curli fibers; extracellular matrix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria
  • Biofilms
  • Biology
  • Escherichia coli Proteins*
  • Escherichia coli* / genetics
  • Extracellular Matrix / chemistry


  • Escherichia coli Proteins