Plastic phenotypic resistance to predation by Bdellovibrio and like organisms in bacterial prey

摘要

Predation at the lowest trophic level, i.e. between bacteria, is poorly understood, hindering efforts to assess its impact on the structure of bacterial communities. The interaction of Bdellovibrio and Bacteriovorax 9Bdellovibrio and like organisms, BLOs), a group of obligate, ubiquitous predatory bacteria, with their Gram0negative bacteriual prey results in the multiplication of the predator and in the lysis, but not in the eradication, of the prey. We show that the residual, surviving population of prey cells exposed to predation stress differ from the populations before exposure as they exhibit increased resistance to predation. This resistance was demonstrated in a number of Gram-negative prey. Moreover, predation resistance is not specific for the BLO strain experienced by the prey. The phenomenon does not stem from a mutation but is a plastic response assocaited with a phenotypic change, and it disappears upon removal of the predator. As resistance to predation is not total, this mechanism can ensures survival of both predator and prey.