Premium
Design and Characterization of an Aequorin‐based Bacterial Biosensor for Detection of Toluene and Related Compounds
Author(s) -
Zeinoddini Mehdi,
Khajeh Khosro,
Behzadian Farida,
Hosseinkhani Saman,
Saeedinia AliReza,
Barjesteh Hesam
Publication year - 2010
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2010.00775.x
Subject(s) - aequorin , bioreporter , bioluminescence , biosensor , activator (genetics) , microbiology and biotechnology , operon , chemistry , lac operon , promoter , escherichia coli , biology , biochemistry , reporter gene , gene expression , receptor , gene , intracellular
An aequorin‐based Escherichia coli strain JM109 biosensor was constructed and characterized for its potential to detect toluene and related compounds in aqueous solutions. The biosensor was constructed based on a PGL2 plasmid carrying the lower pathway promoter (Pu) of the xyl operon of Pseudomonas putida mt‐2 , which was incorporated with transcriptional activator xylR and fused to aequorin cDNA named pGL2 ‐aequorin. Binding of xylR protein to a subset of toluene‐like compounds activates transcription at the Pu promoter, thus expression of aequorin is controlled by xylR and Pu. In this work we have compared the effect of Shine‐Dalgarno (SD) and T2 rrnβ terminator sequence in the expression of aequorin. According to the sensitivity of aequorin and increase in the signal‐to‐noise ratio, this reporter enzyme has reasonable sensitivity compared with other reporter systems. The results indicate higher expression of aequorin in the presence of SD and T2 rrnβ . The activity of aequorin in recombinant whole‐cell biosensor was linear from 1 to 500 μ m of toluene. The bioluminescence response was specific for toluene‐like molecules, so this biosensor cells would be able to detect toluene derivative contamination in environmental samples, accurately.