Bacterial Bioluminescence: Applications in Food Microbiology

Many marine microorganisms ( Vibrio , Photobacterium ) are capable of emitting light, that is, they are bioluminescent. The light-yielding reaction is catalyzed by a luciferase, and it involves the oxidation of reduced riboflavin phosphate and a long-chain aldehyde in the presence of oxygen to produce a blue green light. The genes responsible for the luciferase production, (lux A and lux B), aldehyde synthesis (lux C, D, and E), and regulation of luminescence (lux I and lux R) have all been identified, and recent research has resulted in the discovery of three new genes (lux F, G, and H). The ability to genetically engineer dark microorganisms to become light emitting by introducing the lux genes into them has opened up a wide range of applications of bioluminescence. Assays using bacterial bioluminescence for the detection and enumeration of microorganisms are rapid, sensitive, accurate, and can be made specific. It is these attributes that are making in vivo bioluminescent assays so attractive to the food industry.