Email updates

Keep up to date with the latest news and content from BMC Microbiology and BioMed Central.

Open Access Research article

Spatial distributions of Pseudomonas fluorescens colony variants in mixed-culture biofilms

Matthew L Workentine12, Siyuan Wang1, Howard Ceri1 and Raymond J Turner1*

Author Affiliations

1 Biofilm Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr NW, AB, T2N 1N4, Calgary, Canada

2 Department of Medicine, McMaster University, 1200 Main St W, ON, L8S 4K1, Hamilton, Canada

For all author emails, please log on.

BMC Microbiology 2013, 13:175  doi:10.1186/1471-2180-13-175

Published: 28 July 2013

Abstract

Background

The emergence of colony morphology variants in structured environments is being recognized as important to both niche specialization and stress tolerance. Pseudomonas fluorescens demonstrates diversity in both its natural environment, the rhizosphere, and in laboratory grown biofilms. Sub-populations of these variants within a biofilm have been suggested as important contributors to antimicrobial stress tolerance given their altered susceptibility to various agents. As such it is of interest to determine how these variants might be distributed in the biofilm environment.

Results

Here we present an analysis of the spatial distribution of Pseudomonas fluorescens colony morphology variants in mixed-culture biofilms with the wildtype phenotype. These findings reveal that two variant colony morphotypes demonstrate a significant growth advantage over the wildtype morphotype in the biofilm environment. The two variant morphotypes out-grew the wildtype across the entire biofilm and this occurred within 24 h and was maintained through to 96 h. This competitive advantage was not observed in homogeneous broth culture.

Conclusions

The significant advantage that the variants demonstrate in biofilm colonization over the wildtype denotes the importance of this phenotype in structured environments.