Who turned on the lights?: What the regulation of bacterial bioluminescence tells us about this and other bacterial group behaviours

Abstract

Luminescence produced by organisms, or ‘bioluminescence’, holds a distinct fascination for humankind, and the study of bacterial bioluminescence has a long history in the field of microbiology. Advances in our understanding of bacterial bioluminescence have in many ways paralleled advances in the field as a whole. Intriguingly, studies of bioluminescent bacteria led to a seminal discovery in bacterial gene regulation and behaviour, because for bacteria, bioluminescence is a group activity. Bioluminescent bacteria communicate using pheromones, and as a result the regulatory decision to induce bioluminescence is only made if a group of bacteria has achieved a dense enough population to allow the build-up of pheromone. More recently, it has become clear that there are complex regulatory circuits governing not only luminescence, but also pheromone signalling itself. These additional layers of regulation pose new questions such as what are bacteria really saying to each other? Understanding regulation may also help answer ancient questions including, what use is luminescence?