Autoinduction of bacterial luciferase. Occurrence, mechanism and significance.

The synthesis of the luminous system of the marine luminous bacterium Photobacterium fischeri is subject to a complex, self-regulated control system called autoinduction. The bacteria produce an autoinducer which accumulates in the medium at a constant rate (as a function of cell growth). When autoinducer reaches a critical concentration it stimulates, at the level of transcription, the synthesis of the luminous system. Autoinduction is thus viewed as an environmental sensing mechanism, which curtails the synthesis of the luminous system under dilute conditions. For several isolates of P. fischeri it was found that variations in luminescence intensity could be accounted for by correlated variations in autoinducer production.