luciferase is a generic name for an enzyme that catalyzes a light-emitting reaction. luciferases can be found in bacteria, algae, fungi, jellyfish, insects, shrimp, and squid, and the resulting light that these organisms produce is termed bioluminescence. in bacteria, the genes responsible for the light-emitting reaction (the "lux" genes) have been isolated and used extensively in the construction of bioreporters that emit a blue-green light with a maximum intensity at 490 nm. three variants of "lux" are available, one that functions at < 30°c, another at < 37°c, and a third at < 45°c. the "lux" genetic system consists of five genes, "luxa", "luxb", "luxc", "luxd", and "luxe". depending on the combination of these genes used, several different types of bioluminescent bioreporters can be constructed.