Role of Predators in the Reversal of Imbalances in Microbial Ecosystems

Abstract

MICROBIAL communities contain a wide variety of microorganisms living together, frequently at high population densities. These communities are relatively stable and not easily disturbed. When a heterogeneous animal or plant population becomes unbalanced by a minor ecological disturbance, such as immigration of a foreign species or by a temporary change in nutrient concentration, the community structure may be altered permanently. By contrast, microbial populations developed either by intrusion of non-indigenous microorganisms or by temporary ecological perturbations are vigorously resisted by the native community. Intermicrobial predators exist in most microbial communities. This communication describes the homeostatic processes by which microbial imbalances are reversed by predators among the native population.