But when the virus infects its host, for example the salmonella, the spliced enzyme genes cause the salmonella bacteria to glow. Devices such as these which combine a rapid detection system with a microprocessor to provide the results of a specific biological reaction are called biosensors. Using the luminometer, a reading of bacteria levels can be obtained in a few seconds. Processing the information with a computer means results can be obtained in a few minutes. Bacterial bioluminescence is useful for determining the exact source of bacterial contamination which may occur in food processing activities such as cutting or tenderizing.
Scientists can also monitor whether methods of destroying or reducing bacteria are working.
They also get a better understanding of the conditions which help bacteria grow and how these microorganisms are transferred from one surface to another. Bioluminescence tests also offer scientists the advantage of being able to work with a particular sample under various conditions. It was found that the bacteria simply go into suspended animation at freezing temperatures, and can recover easily when meats are thawed at room temperature. At refrigerator temperature, salmonella are not able to function very efficiently. In addition, other harmless bacteria that operate well in cool temperatures compete with the salmonella.