7. Concluding remarks
Marine luminescent bacteria make up the largest fraction of light-emitting organisms. The biochemical reactions leading to light emission by bacteria have been examined in great detail. The genetic regulation of the efficiency of bacterial luminescence is a fascinating process, and provides an example of how bacterial cells can communicate with each other (the quorum sensing mechanism). Recent studies have shed new light on a problem that has long remained unsolved, i.e. the biological role of bacterial luminescence. It seems that bacteria emit light to stimulate DNA repair. Moreover, luciferase activity may be important in the detoxification of deleterious oxygen derivatives. The discovery of the biological roles of luminescence may, in turn, help us to understand the early stages in the evolution of this process, a problematic aspect of the Darwinian theory. Finally, apart from being models in basic research, luminescent marine bacteria have potential biotechnological applications, mainly in the detection of mutagenic and toxic compounds in marine environments.