Review article

Social Interactions and Biofilm Formation in Bacillus subtilis

Iztok Dogsa ; University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Chair of Microbiology, Večna pot 111, SI-1000 Ljubljana, Slovenia
Anna Oslizlo ; University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Chair of Microbiology, Večna pot 111, SI-1000 Ljubljana, Slovenia
Polonca Stefanic ; University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Chair of Microbiology, Večna pot 111, SI-1000 Ljubljana, Slovenia
Ines Mandic-Mulec ; University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Chair of Microbiology, Večna pot 111, SI-1000 Ljubljana, Slovenia

Abstract

Quorum sensing (QS) is a form of cooperative social behaviour which relies on extracellular signalling molecules that elicit the QS response across many cells and controls the development of many cooperative traits including biofilm formation. The main aim of this work is to review the published work on cooperative social behaviour of Bacillus subtilis and especially its QS system ComQXPA. This QS system involves four interacting components: the signal-processing enzyme ComQ, the ComX signal, the ComP receptor and the ComA transcriptional regulator. Phosphorylated ComA controls the transcription of many genes including those responsible for the production of surfactin and extracellular matrix, essential for biofilm formation. The ComQXPA QS shows a high degree of genetic polymorphism, which manifests itself in the separation of Bacillus subtilis strains into four different communication groups (pherotypes). The information exchange is possible between members of the same pherotype but not across pherotypes. We have recently suggested that this phenomenon is at least in part driven by the ecological divergence of strains, but may also be induced by frequency-dependent selection. The ComQXPA QS system controls the production of extracellular matrix (ECM) components: polysaccharides, proteins and nucleic acids. We will address the present understanding of the ECM structure-function relationships in B. subtilis biofilms and review published results on regulation, composition and distribution of ECM components. Despite many important recent discoveries on regulation of B. subtilis biofilm development, we know little about the molecular interactions in the ECM and the role they play in the QS and stability of the biofilm. Future research needs to address these questions better.

Keywords

quorum sensing; Bacillus subtilis; biofilm formation; ComQXPA system; extracellular matrix components; surfactin

Hrčak ID:

122339

URI

https://hrcak.srce.hr/122339

Publication date:

15.6.2014.

Article data in other languages: croatian

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