Do Bacteria Gossip? Quorum Sensing: The Chemical ‘Gossip’ between Species

Resumo

Bacterial communication through Quorum sensing coordinates group behaviours based on population
density using chemical signals called autoinducers. This review explores the diversity of these signals,
including acyl-homoserine lactones and autoinducing peptides specific to Gram-negative and Gram-positive
bacteria, respectively, as well as inter-species signals like autoinducer-2, autoinducer-3, and indole. It details
the molecular mechanisms underlying signal synthesis, detection (often via two-component systems or
LuxR-type regulators), and downstream gene regulation controlling processes such as virulence, biofilm
formation, bioluminescence, and competence. Furthermore, the manuscript discusses how environmental
factors like nutrient availability, carbon sources, and stress conditions, integrated through mechanisms
like the stringent response and catabolite repression, modulate Quorum sensing networks. The profound
ecological significance of Quorum sensing is highlighted through examples of inter-species cross-talk,
host-microbe interactions in pathogenesis and symbiosis, plant-microbe associations, and communication
within complex marine ecosystems, demonstrating its crucial role in shaping microbial communities and
their interactions with multicellular organisms.