title: Quorum sensing triggers the stochastic escape of individual cells from Pseudomonas putida biofilms.
abstract: The term 'quorum sensing' (QS) is generally used to describe the phenomenon that bacteria release and perceive signal molecules to coordinate cooperative behaviour in response to their population size. QS-based communication has therefore been considered a social trait. Here we show that QS signals (N-acyl-homoserine lactones, AHLs) are stochastically produced in young biofilms of Pseudomonas putida and act mainly as self-regulatory signals rather than inducing neighbouring cells. We demonstrate that QS induces the expression of putisolvin biosurfactants that are not public goods, thereby triggering asocial motility of induced cells out of microcolonies. Phenotypic heterogeneity is most prominent in the early stages of biofilm development, whereas at later stages behaviour patterns across cells become more synchronized. Our findings broaden our perspective on QS by showing that AHLs can control the expression of asocial (self-directed) traits, and that heterogeneity in QS can serve as a mechanism to drive phenotypic heterogeneity in self-directed behaviour.
authors.affiliation: Department of Microbiology, Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, Zürich CH-8008, Switzerland.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Cárcamo-Oyarce
authors.affiliation: Department of Microbiology, Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, Zürich CH-8008, Switzerland.
authors.forename: Putthapoom
authors.initials: P
authors.lastname: Lumjiaktase
authors.affiliation: Department of Microbial Evolutionary Ecology, Institute of Plant Biology, University of Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland.
authors.forename: Rolf
authors.initials: R
authors.lastname: Kümmerli
authors.affiliation: Department of Microbiology, Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, Zürich CH-8008, Switzerland.
authors.forename: Leo
authors.initials: L
authors.lastname: Eberl
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D016958:Pseudomonas putida / Q000254:growth & development / Q000378:metabolism*; D053038:Quorum Sensing / Q000502:physiology*
chemical_list: D054742:Acyl-Butyrolactones