Editor: Riks Laanbroek
Effects of nutrient availability and Ochromonas sp. predation on size and composition of a simplified aquatic bacterial community
Version of Record online: 25 JUL 2006
FEMS Microbiology Ecology
Volume 58, Issue 3, pages 354–363, December 2006
How to Cite
Corno, G. (2006), Effects of nutrient availability and Ochromonas sp. predation on size and composition of a simplified aquatic bacterial community. FEMS Microbiology Ecology, 58: 354–363. doi: 10.1111/j.1574-6941.2006.00185.x
- Issue online: 25 JUL 2006
- Version of Record online: 25 JUL 2006
- Received 7 December 2005; revised 14 April 2006; accepted 2 June 2006.First published online 25 July 2006.
- grazing on bacteria;
- prey–predator interaction;
- phenotypic adaptation;
Predation and competition are two main factors that determine the size and composition of aquatic bacterial populations. Using a simplified bacterial community, composed of three strains characterized by different responses to predation, a short-term laboratory experiment was performed to evaluate adaptations and relative success in communities with experimentally controlled levels of predation and nutrient availability. A strain with a short generation time (Pseudomonas putida), one with high plasticity in cell morphology (Flectobacillus sp. GC5), and one that develops microcolonies (Pseudomonas sp. CM10), were selected. The voracious flagellate Ochromonas sp. was chosen as a predator. To describe adaptations against grazing and starvation, abundance, biomass and relative heterogeneity of bacteria were measured. On the whole, the strains in the predation-free cultures exhibited unicellular growth, and P. putida represented the largest group. The presence of Ochromonas strongly reduced bacterial abundance, but not always the total biomass. The activity of grazers changed the morphological composition of the bacterial communities. Under grazing pressure the relative composition of the community depended on the substrate availability. In the presence of predators, P. putida abundance declined in both high and low nutrient treatments, and Pseudomonas CM10 developed colonies. Flectobacillus was only numerically codominant in the nutrient-rich environments.