Focusing now on bioluminescent bact

Focusing now on bioluminescent bacteria, these are simply light-emitting bacteria, a result of biochemical reaction catalysed by an enzyme ‘luciferase’. The property of bacteria to produce luciferase is not only most widely studied in Vibrio fischeri but also found in the other species of Vibrio like V. alginolyticus. As we already have a lab strain of V. alginolyticus, we pursued in vitro studies with this strain. At genomic level, the light emitting process is regulated in a very strict manner by a cluster of genes known as lux operon. At low cell density the autoinducer (OhHSL), which is produced, diffuses into environment, and the concentration of autoinducer increases as cells continue to grow in mass, resulting in high level of autoinducers in the environment. At high cell density, OhHSL concentration rises above the threshold that creates a regulatory response leading to expression of luxICDABE genes and produces bioluminescence [25]. Various kinds of toxic materials such as heavy metals, pesticides and other industrial effluents can cause dramatic and measurable effect on the bacterial system responsible for light production and this phenomenon is exploited by researchers as bioluminescence inhibition assay. However, till date bioluminescence inhibition has not been performed using QSI molecules.