Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | Direct and Indirect Effects of Protist Predation on Population Size Structure of a Bacterial Strain with High Phenotypic Plasticity |
| Abstract | We studied the impact of grazing and substrate supply on the size structure of a freshwater bacterial strain (Flectobacillus sp.) which showed pronounced morphological plasticity. The cell length varied from 2 to >40 um and encompassed rods, curved cells, and long filaments. Without grazers and with a sufficient substrate supply, bacteria grew mainly in the form of medium-sized rods (4 to 7 um), with a smaller proportion (<10%) of filamentous forms. Grazing experiments with the bacterivorous flagellate Ochromonas sp. showed that freely suspended cells of <7 um were highly vulnerable to grazers, whereas filamentous cells were resistant to grazing and became enriched during predation. A comparison of long-term growth in carbon-limited chemostats with and without grazers revealed that strikingly different bacterial populations developed: treatments with flagellates were composed of >80% filamentous cells. These attained a biomass comparable to that of populations in chemostats without grazers, which were composed of medium-sized rods and c-shaped cells. Carbon starvation resulted in a fast decrease in cell length and a shift towards small rods, which were highly vulnerable to grazing. Dialysis bag experiments in combination with continuous cultivation revealed that filament formation was significantly enhanced even without direct contact of bacteria with bacterivores and was thus probably stimulated by grazer excretory products |
| Source | Applied and environmental microbiology (Print) 72(1), pp. 78–86 |
| Keywords | grazing on bacteriapreypredator interactionphenotypic adaptationfilamentmicrocolony |
| Journal | Applied and environmental microbiology (Print) |
| Editor | American Society for Microbiology., [Washington], Stati Uniti d'America |
| Year | 2006 |
| Type | Articolo in rivista |
| Authors | Corno G., Jürgens K. (1) |
| Text | 52955 2006 grazing on bacteria preypredator interaction phenotypic adaptation filament microcolony Direct and Indirect Effects of Protist Predation on Population Size Structure of a Bacterial Strain with High Phenotypic Plasticity Corno G., Jurgens K. 1 1 Biologische Meereskunde, Institut fur Ostseeforschung Warnemunde We studied the impact of grazing and substrate supply on the size structure of a freshwater bacterial strain Flectobacillus sp. which showed pronounced morphological plasticity. The cell length varied from 2 to >40 um and encompassed rods, curved cells, and long filaments. Without grazers and with a sufficient substrate supply, bacteria grew mainly in the form of medium sized rods 4 to 7 um , with a smaller proportion <10% of filamentous forms. Grazing experiments with the bacterivorous flagellate Ochromonas sp. showed that freely suspended cells of <7 um were highly vulnerable to grazers, whereas filamentous cells were resistant to grazing and became enriched during predation. A comparison of long term growth in carbon limited chemostats with and without grazers revealed that strikingly different bacterial populations developed treatments with flagellates were composed of >80% filamentous cells. These attained a biomass comparable to that of populations in chemostats without grazers, which were composed of medium sized rods and c shaped cells. Carbon starvation resulted in a fast decrease in cell length and a shift towards small rods, which were highly vulnerable to grazing. Dialysis bag experiments in combination with continuous cultivation revealed that filament formation was significantly enhanced even without direct contact of bacteria with bacterivores and was thus probably stimulated by grazer excretory products 72 1 Published version Articolo in rivista American Society for Microbiology. 0099 2240 Applied and environmental microbiology Print Applied and environmental microbiology Print Appl. environ. microbiol. Print Applied and environmental microbiology. Print gianluca.corno CORNO GIANLUCA TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici |