A microbial whole-cell biosensor was developed, and its potential to measure water-dissolved concentrations of middle-chain-length @entity19765 and some related compounds by bioluminescence was characterized. The biosensor strain @entity27600 alpha(pGEc74, pJAMA7) carried the regulatory gene alkS from Pseudomonas oleovorans and a transcriptional fusion of PalkB from the same strain with the promoterless luciferase luxAB genes from @entity11784 on two separately introduced plasmids. In standardized assays, the biosensor cells were readily inducible with @entity14143 , a typical inducer of the alk system. Light emission after induction periods of more than 15 min correlated well with @entity14143 concentration. In well-defined aqueous samples, there was a linear relationship between light output and @entity14143 concentrations between 24 and 100 nM. The biosensor responded to middle-chain-length @entity19765 but not to alicyclic or aromatic compounds. In order to test its applicability for analyzing environmentally relevant samples, the biosensor was used to detect the bioavailable concentration of @entity19765 in heating oil-contaminated groundwater samples. By the extrapolation of calibrated light output data to low @entity14143 concentrations with a hyperbolic function, a total inducer concentration of about 3 nM in @entity14143 equivalents was estimated. The whole-cell biosensor tended to underestimate the @entity2292 concentration in the groundwater samples by about 25%, possibly because of the presence of unknown inhibitors. This was corrected for by spiking the samples with a known amount of an @entity14143 standard. Biosensor measurements of @entity2292 concentrations were further verified by comparing them with the results of chemical analyses.

Development and characterization of a whole-cell bioluminescent sensor for bioavailable middle-chain XXXX in contaminated groundwater samples.

@entity27600 :: ('536056', 'Species') :: ['Escherichia coli DH5'] @entity11784 :: ('669', 'Species') :: ['Vibrio harveyi'] @entity19765 :: ('MESH:D000473', 'Chemical') :: ['alkanes'] @entity14143 :: ('MESH:C026728', 'Chemical') :: ['octane'] @entity2292 :: ('CHEBI:18310', 'Chemical') :: ['alkane']
@entity19765 :: (MESH:D000473,Chemical) :: ['alkanes']
