Physiological, biochemical and genetic control of bacterial bioluminescence.

Publisher Summary The bioluminescent bacteria comprise one of several groups of luminous organisms. Significant differences exist between the bioluminescence reactions of different organisms, including the structure and properties of the luciferases and substrates. Molecular oxygen is the only common feature of bioluminescence reactions, indicating that the luminescent systems in most organisms may have evolved independently. Luminescent bacteria are present in marine environment, freshwater, and terrestrial habitats. They can occur as free-living forms, saprophytes, commensal symbionts, parasites of animals, and specific light-organ symbionts. The luminescence produced by these bacteria, because of its inherent beauty and ease of detection, has attracted scientific attention. With the use of molecular approaches to study the luminescence systems of these bacteria, population biology, ecology, and molecular mechanisms of luminescence (lux) gene regulation can be studied. This chapter describes the current status of bioluminescent systems of luminous bacteria, emphasizing the biochemistry, lux gene organization, and the physiological and genetic regulation of lux gene expression. The effects of oxygen on luminescence illustrate the application of bacterial luminescence system as a sensor of specific molecules that affect metabolic function and gene expression. Knowledge of the basic biochemistry, molecular biology, and physiology of luminescent bacteria is thus not only of interest but of importance for future scientific endeavors.