Present address: Laura Oberhaus, Paris-Universitas, Environmental Research and Teaching Institute (CERES-ERTI), Ecole Normale Supérieure, Paris, France.
Allelopathic growth inhibition by the toxic, bloom-forming cyanobacterium Planktothrix rubescens
Article first published online: 22 AUG 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Ecology
Volume 66, Issue 2, pages 243–249, November 2008
How to Cite
Oberhaus, L., Briand, J.-F. and Humbert, J.-F. (2008), Allelopathic growth inhibition by the toxic, bloom-forming cyanobacterium Planktothrix rubescens. FEMS Microbiology Ecology, 66: 243–249. doi: 10.1111/j.1574-6941.2008.00567.x
Editor: Riks Laanbroek
- Issue published online: 14 OCT 2008
- Article first published online: 22 AUG 2008
- Received 8 April 2008; revised 20 June 2008; accepted 4 July 2008.First published online 22 August 2008.
Blooms of freshwater cyanobacteria are typically accompanied by an important decrease in phytoplankton biodiversity in the water bodies where they occur. This study examines the potential production of growth-inhibiting substances by the toxic, bloom-forming cyanobacterium Planktothrix rubescens, following the observation of physical segregation between this and another cyanobacterium during previously performed mixed-culture competition experiments. Inhibition assays examining the growth of target strains exposed to donor culture filtrates showed that the growth of Planktothrix agardhii TCC 83-2, P. agardhii PMC 75.02 and Mougeotia gracillima TCC 50-2 was significantly inhibited in the presence of culture filtrate from P. rubescens TCC 29-1, isolated from Lake Bourget, France. Filtrates from P. rubescens TCC 69-6 and P. rubescens TCC 69-7, isolated from Lakes Nantua and Paladru (France), respectively, did not, however, inhibit the growth of P. agardhii TCC 83-2. This brief exploration of the allelopathic activity of P. rubescens suggests that it may potentially inhibit coexisting competitors as well as phytoplankton isolated from other freshwater ecosystems, and that this capacity may vary among different strains of Planktothrix. The potential importance of this phenomenon in pelagic competition dynamics is discussed.