title: Differential growth of wrinkled biofilms.
abstract: Biofilms are antibiotic-resistant bacterial aggregates that grow on moist surfaces and can trigger hospital-acquired infections. They provide a classical example in biology where the dynamics of cellular communities may be observed and studied. Gene expression regulates cell division and differentiation, which affect the biofilm architecture. Mechanical and chemical processes shape the resulting structure. We gain insight into the interplay between cellular and mechanical processes during biofilm development on air-agar interfaces by means of a hybrid model. Cellular behavior is governed by stochastic rules informed by a cascade of concentration fields for nutrients, waste, and autoinducers. Cellular differentiation and death alter the structure and the mechanical properties of the biofilm, which is deformed according to Föppl-Von Kármán equations informed by cellular processes and the interaction with the substratum. Stiffness gradients due to growth and swelling produce wrinkle branching. We are able to reproduce wrinkled structures often formed by biofilms on air-agar interfaces, as well as spatial distributions of differentiated cells commonly observed with B. subtilis.
authors.affiliation: Centro Nacional de Biotecnología, CSIC, Madrid 28049, Spain.
authors.forename: D R
authors.initials: DR
authors.lastname: Espeso
authors.affiliation: Departamento de Matematica Aplicada, Universidad Complutense, Madrid 28040, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Carpio
authors.affiliation: Center for Complex and Nonlinear Science, UC Santa Barbara, California 93106, USA.
authors.forename: B
authors.initials: B
authors.lastname: Einarsson
mesh_terms: D000362:Agar; D000388:Air; D001412:Bacillus subtilis / Q000502:physiology*; D018441:Biofilms; D016923:Cell Death; D002454:Cell Differentiation; D003198:Computer Simulation; D004548:Elasticity; D008954:Models, Biological; D013269:Stochastic Processes; D013499:Surface Properties; D014867:Water
chemical_list: D014867:Water; D000362:Agar