Strategies and mechanisms of contact-dependent predation in bacteria.

Predatory bacteria kill other bacteria to acquire nutrients. Among diverse strategies to kill and feed on prey, contact-dependent predation stands out as it requires direct physical interaction between predator and prey. By delving into the mechanisms of contact-dependent predation among bacteria, this review illustrates the breadth of molecular and cellular determinants underlying these remarkable antagonistic interactions. We highlight structural, genetic, and imaging evidence supporting the roles of envelope protein machineries - pili and secretion systems - as well as adhesins and specialised membrane junctions, in mediating key steps of contact-dependent predation. Although detailed mechanistic understanding remains scarce, recurring themes reveal the repurposing of molecular devices that may undergo precise regulation to achieve predatory actions at the right place and time. Future research should identify the molecular nature of prey-predator interfaces and uncover how prey contact and consumption integrate with other cellular processes, potentially revealing novel bacterial cell cycle control pathways.