Cell damage detection using Escherichia coli reporter plasmids: fluorescent and colorimetric assays

Abstract

be used in semiquantitative (fluorometric) and qualitative (β-galactosidase activity) studies of different xenobiotic substances and pollutants.

Potential Applications of the Escherichia coli Heat Shock Response in Synthetic Biology

“…In E. coli, HS promoters have been used to construct biosensors or toxicity reporters. Whole-cell biosensors or reporter strains are easy to construct and are fast and reliable tools [32]. The expression of a reporter gene (e.g., encoding b-galactosidase, luciferase, or a fluorescent protein) is activated with a specific stimulus and can be useful to detect toxic compounds or to understand the behavior of bacteria when exposed to pollutants, xenobiotics, and other compounds that represent a threat to living organisms [32].…”

“…The expression of a reporter gene (e.g., encoding b-galactosidase, luciferase, or a fluorescent protein) is activated with a specific stimulus and can be useful to detect toxic compounds or to understand the behavior of bacteria when exposed to pollutants, xenobiotics, and other compounds that represent a threat to living organisms [32]. The HSR can be activated by different types of stress such as HS, nutrient limitation (amino acids), or the addition of IPTG (isopropyl b-D-1-thiogalactopyranoside), ethanol, phenol acetic acid, antifoam, or salt (osmotic shock), among others [17,32,33]. For example, the E. coli HS promoters of dnaK, ibpA, and grpE were fused to luciferase (luxCDABE operon) from Vibrio fischeri, which confers bioluminescent properties [34][35][36].…”

“…Green fluorescent protein (GFP) from Aequorea victoria has also been fused to HS promoters (rpoH, clpB, dnaK, ibpA, and fxsA) [17,32,33]. Fusions of gfp and lux to the grpE HS promoter were compared, and lux was found to be more efficient as a reporter because the GFP fluorescence signal developed much more slowly and the induction ratio was lower [38].…”

<i>Escherichia coli</i> as a Model Organism and Its Application in Biotechnology

“…E. coli-based biosensors using plasmid or chromosomal constructs are useful for the detection of environmental traits or hazards or measuring cellular processes as any standard reporter system [68][69][70].…”

“…Biosensors based on whole cells are a cheap alternative and can be coupled to portable devices. Using qualitative reporters can be applied in ield research [70]. One good example is the detection of parasites without using cold-protected samples or complicated equipment for the detection process [86].…”