Luminescent Bacterial Biosensors for the Rapid Detection of Toxicants

Abstract

There is an increasing demand for sensitive and user‐friendly biological assays for the rapid and cost effective assessment of environmental contaminants in soil, sediment, and water ecosystems. Luminescent bacterial biosensors have emerged as promising tools in environmental monitoring for the sensitive and specific quantification of both toxicity and bioavailability. The naturally luminescent marine bacterium Vibrio fischeri has been extensively employed to assess the toxicity of a wide range of pollutants. In addition, recent advances in reporter gene technology have led to the development of many luminescent‐marked bacterial biosensors. Some of the bacterial biosensors that have been constructed are used for general toxicity testing, as they constitutively express luminescence and respond to toxicants in a “lights off” manner. Another class of biosensors have been developed which react to toxicants in a “lights on” manner, where light production is induced by bioavailable concentrations of toxicants. These microbial biosensors offer a powerful new approach to environmental monitoring, providing an indication of the bioavailabilty of specific pollutants in complex environments, rather than the total concentration obtained by traditional analytical techniques. Here the focus is on the use of both natural and genetically engineered luminescent bacterial biosensors for the assessment of toxicity and bioavailability.