Microbial Interactions: Predation

Microbial predation is the process by which a microbe kills and consumes another to gain nutrients.

Some predatory bacteria are described as epibiotic or endobiotic based on their strategies.

Epibiotic predators like Vampirococcus attach to the prey’s outer membrane, secrete lytic enzymes, and absorb released cytoplasmic material.

Endobiotic predators, like Bdellovibrio, initiate their life cycle by attaching to a prey cell and penetrating its outer membrane to enter the periplasmic space.

Once inside, the predator converts the host into a spherical bdelloplast. It then elongates and replicates, lysing the host to release progeny.

Myxococcus can prey on other microbes but also grows saprotrophically on organic matter.

During predation, coordinated Myxococcus populations use gliding motility to approach and swarm over prey, releasing enzymes and antibiotics that lyse the prey cells.

Predatory protozoans graze on bacteria, helping transfer carbon and energy up the food web.

To defend against grazing, bacteria often form larger structures like filaments, microcolonies, or biofilms.