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Measuring mass transfer processes of octane with the help of an alkS alkB::gfp ‐tagged Escherichia coli
Author(s) -
Jaspers Marco C. M.,
Meier Christoph,
Zehnder Alexander J. B.,
Harms Hauke,
Van Der Meer Jan Roelof
Publication year - 2001
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1046/j.1462-2920.2001.00218.x
Subject(s) - octane , microscale chemistry , escherichia coli , alkb , green fluorescent protein , aqueous solution , fluorescence , aqueous two phase system , fluorescence microscope , biophysics , analytical chemistry (journal) , biology , chromatography , chemistry , biochemistry , organic chemistry , physics , mathematics education , mathematics , quantum mechanics , gene
Diffusion of octane from oily droplets in different microscale settings was measured using Escherichia coli expressing the stable green fluorescent protein (GFP) from the alkB promoter of Pseudomonas oleovorans . GFP fluorescence intensities were determined quantitatively at the single‐cell level after 1.0 or 2.5 h incubation and compared with different calibration series using known concentrations of octane. By immobilizing the E. coli sensor cells on the bottom glass plate of a microscope flow chamber, it was possible to monitor the diffusion process for octane in aqueous solution as a function of time and distance from non‐aqueous phase droplets of octane alone or oily octane mixtures. When a gas phase was included in the flow chambers, octane transport could be demonstrated from the oily mixtures to the cells through both gas and liquid phase. Assays of non‐immobilized sensor cells in microdroplets in the presence or absence of soil particles incubated with octane through the vapour phase revealed a slight reduction in the total amount of induced E. coli cells in the presence of soil. Our results indicate the power of using GFP‐marked single‐cell biosensors in determining microscale bioavailability of organic pollutants.