Document Type

Article

Publication Date

6-2017

Publication Source

mBio

Abstract

Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa. We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides populationlevel benefits in biofilms, for both growth and antibiotic tolerance; (iii) the benefits of PSL production are social and are shared with other cells; (iv) the benefits of PSL production appear to be preferentially directed toward cells which produce PSL; (v) cells which do not produce PSL are unable to successfully exploit cells which produce PSL. Taken together, this suggests that PSL is a social but relatively nonexploitable trait and that growth within biofilms selects for PSL-producing strains, even when multiple strains are on a patch (low relatedness at the patch level).

Inclusive pages

1013

ISBN/ISSN

2150-7511

Document Version

Published Version

Comments

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (CC-BY).

Journal website

Publisher

American Society for Microbiology

Volume

8

Issue

3

Peer Reviewed

yes

Keywords

Pseudomonas aeruginosa, social evolution, biofilms