Bioluminescence is the production and emission of light by a living organism. It is a form of chemiluminescence, where light is produced by a chemical reaction. This phenomenon is widespread, especially in marine environments, and is utilized by a diverse range of organisms including bacteria, fungi, insects, and fish. The chemical reaction involves a light-emitting molecule called a luciferin and an enzyme called a luciferase, which catalyzes the oxidation of luciferin, releasing energy in the form of light. The color of the light depends on the chemical structure of the luciferin and the specific enzyme.
The observation of bioluminescence dates back to ancient times, with Greek philosophers like Aristotle mentioning the glow of fireflies and dead fish. However, the scientific investigation began in the late 16th and 17th centuries. Sir Francis Bacon noted that seawater could sometimes glow, and Robert Boyle in the 1660s demonstrated that the light from glowing wood and fish required air (oxygen). The term "luciferin" was first coined by French scientist Raphaël Dubois in the late 1880s from his work on click beetles and clams, where he isolated the two key components of the light-producing reaction.
Bioluminescence has evolved independently at least 40 times, showcasing its significant evolutionary advantage. In the deep ocean, where sunlight is absent, it is estimated that up to 90% of organisms are bioluminescent. It serves various purposes: defense (startling predators, camouflage), offense (luring prey), and communication (attracting mates). Beyond its natural significance, the study of bioluminescence has had a profound impact on science and technology. Luciferin-luciferase systems are fundamental tools in molecular biology, used in genetic engineering, medical imaging, and as reporter genes to study cellular processes and disease progression. Commercial applications include toxicity testing and food safety analysis.