title: The MyxobacteriumMyxococcus xanthusCan Sense and Respond to the Quorum Signals Secreted by Potential Prey Organisms.
abstract: The myxobacteriumMyxococcus xanthusis a predatory member of the soil microfauna, able to consume bacteria (Gram-negative, Gram-positive), archaea, and fungi. Many potential prey ofM. xanthuscommunicate amongst themselves using acyl homoserine lactones (AHLs) as quorum signals.M. xanthuscannot itself produce AHLs, but could potentially benefit by responding to exogenous AHLs produced during signaling between proximal prey. Four AHLs of different side chain length were tested and all found to delay sporulation ofM. xanthusvegetative cells, and to stimulate germination of myxospores, increasing the proportion of predatory vegetative cells in the population. The predatory activity and expansion rates ofM. xanthuscolonies were also found to be stimulated by AHLs. Thermally inactivated AHLs had no effect onM. xanthuscells, and the response to AHLs depended (non-linearly) on the length of AHL side chain, suggesting that the effect of AHLs was mediated by specific signaling withinM. xanthus, rather than being a consequence of the chemical or physical properties of AHLs. Therefore, it seems that the presence of xenic quorum signaling molecules enhances the predatory activity ofM. xanthus. AHLs increase the proportion of the population capable of predation, and stimulate the motility and predatory activity of vegetative cells. We therefore propose that in the wild,M. xanthususes AHLs as markers of nearby prey, potentially eavesdropping on the conversations between prey organisms.
authors.affiliation: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University Ceredigion, UK.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Lloyd
authors.affiliation: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University Ceredigion, UK.
authors.forename: David E
authors.initials: DE
authors.lastname: Whitworth
keywords: Myxococcus xanthus; N-Acyl homoserine lactone; kairomone; predation; predator-prey interaction; signaling; sporulation