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

• Published in: Annual review of microbiology Vol. 75; no. 1; pp. 269 - 290
• Main Authors: Serra, Diego O, Hengge, Regine
• Format: Journal Article
• Language: English
• Published: United States Annual Reviews 08.10.2021; Annual Reviews, Inc
• Subjects: Amyloid; bacterial second messenger; Biofilms; c-di-GMP; Cellulose; curli fibers; E coli; Escherichia coli; Extracellular matrix; Heterogeneity; Homeostasis; Morphogenesis; RpoS; Second messengers; Structure-function relationships; Transcription factors; curli fibers; c-di-GMP; RpoS; bacterial second messenger; cellulose; extracellular matrix
• ISSN: 0066-4227; 1545-3251
• DOI: 10.1146/annurev-micro-031921-055801

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.