The anti-biofilm activity secreted by a marine Pseudoalteromonas strain

Abstract

Bacterial biofilms occur on all submerged structures in marine environments. The authors previously reported that the marine bacterium Pseudoalteromonas sp. 3J6 secretes antibiofilm activity. Here, it was discovered that another Pseudoalteromonas sp. strain, D41, inhibited the development of strain 3J6 in mixed biofilms. Confocal laser scanning microscope observations revealed that the culture supernatant of strain D41 impaired biofilm formation of strain 3J6 and another marine bacterium. A microtiter plate assay of the antibiofilm activity was set up and validated with culture supernatants of Pseudoalteromonas sp. 3J6. This assay was used to determine the spectra of action of strains D41 and 3J6. Each culture supernatant impaired the biofilm development of 13 marine bacteria out of 18. However, differences in the spectra of action and the physical behaviours of the antibiofilm molecules suggest that the latter are not identical. They nevertheless share the originality of being devoid of antibacterial activity against planktonic bacteria.

Keywords:

• biofilm
• Pseudoalteromonas
• marine bacterium
• antibiofilm activity
• biofilm inhibition

Acknowledgements

This work was funded by the Axis 1 ‘Genomics and blue chemistry’ of the GIS Europôle Mer. GLK was the recipient of a doctoral fellowship from IFREMER and the Région Bretagne, France. The authors are grateful to C Sternberg (Department of Systems Biology, Technical University of Denmark) for kindly providing the COMSTAT2 software. They also thank AC Glasgow Karls (Department of Microbiology, University of Georgia, Athens, USA) for providing P. atlantica T6c.

Additional information

Notes on contributors

Chantal Compère

The last two authors equally contributed to this work.