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 microm 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 microm), with a smaller proportion (<10%) of filamentous forms. Grazing experiments with the bacterivorous flagellate Ochromonas sp. showed that freely suspended cells of <7 microm 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

SUBMITTER: Corno G 

PROVIDER: S-EPMC1352273 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature