Abstract
Adherent growth of Pseudomonas putida KT2440 with and without the TOL plasmid (pWWO) at the solid-liquid and air-liquid interface was examined. We compared biofilm formation on glass in flow cells, and assayed pellicle (air-liquid interface biofilm) formation in stagnant liquid cultures by confocal laser scanning microscopy. The TOL-carrying strains formed pellicles and thick biofilms, whereas the same strains without the plasmid displayed little adherent growth. Microscopy using fluorescent nucleic acid- specific stains (cytox orange, propidium iodide) revealed differences in production of extracellular polymeric substances: TOL carriage leads to more extracellular DNA (eDNA) in pellicles and biofilms. Pellicles were dissolved by DNAse I treatment. eDNA was observed as ominous fibrous structures. Quantitative analysis of live and dead cells in static cultures was performed by flow cytometry combined with specific cytostains; release of cytoplasmic material was assayed by a β-glucosidase assay. Enhanced cell lysis due to plasmid carriage was ruled out as the mechanism for eDNA release. We report, for the first time, that carriage of a conjugative plasmid leads to increased biofilm formation by production of eDNA.
| Original language | English |
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| Publication date | 2010 |
| Publication status | Published - 2010 |
| Event | 13th International Symposium on Microbial Ecology - Seattle, WA, United States Duration: 22 Aug 2010 → 27 Aug 2010 Conference number: 13 http://www.isme-microbes.org/isme13 |
Conference
| Conference | 13th International Symposium on Microbial Ecology |
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| Number | 13 |
| Country/Territory | United States |
| City | Seattle, WA |
| Period | 22/08/2010 → 27/08/2010 |
| Internet address |