Quorum sensing and bacterial cross-talk in biotechnology.

Only a decade ago, the secretion and perception of small signalling molecules that in turn are transduced to coordinate behaviour of a 'minimal unit' of microorganisms was termed quorum sensing by EP Greenberg and colleagues. Since then, an explosion (or exponential growth) in understanding and prevalence of quorum-sensing systems has ensued, with sightings ranging from virulence in human and plant pathogens to degradative capacity of activated sludge. Not surprisingly, regulatory mechanisms span traditional inducer/repressor motifs homologous to the lac operon to the recently discovered interfering RNAs. Further characterisation of signalling circuits, coupled with creative niche applications, suggest a wealth of opportunity for advancing commercial biotechnology.