Which bacterium hunts other bacteria by invading and digesting them from within?

Bdellovibrio bacteriovorus hunts other bacteria by invading and digesting them from within.

A free-swimming B. bacteriovorus uses a rapidly rotating flagellum to collide with a prey bacterium, often one with a Gram-negative cell envelope. It attaches, penetrates the prey’s outer layers and enters the space between the prey’s cell membrane and wall.

Inside, the predator reshapes the prey into a structure called a bdelloplast. It consumes the prey’s contents, grows into a filament and eventually divides into several progeny cells that escape to hunt again.

This unusual life cycle makes Bdellovibrio a subject of research on biological control and antibiotic alternatives. It is not the same as Myxococcus xanthus, which attacks collectively using groups of cells and extracellular enzymes rather than following this classic intracellular predatory cycle.