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Use of a whole‐cell biosensor to assess the bioavailability enhancement of aromatic hydrocarbon compounds by nonionic surfactants
Author(s) -
Keane Angela,
Lau Peter C.K.,
Ghoshal Subhasis
Publication year - 2007
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.21524
Subject(s) - phenanthrene , bioavailability , chemistry , pulmonary surfactant , pseudomonas putida , critical micelle concentration , chromatography , biodegradation , micelle , micellar solutions , naphthalene , rhamnolipid , polycyclic aromatic hydrocarbon , environmental chemistry , organic chemistry , biochemistry , bacteria , aqueous solution , pseudomonas aeruginosa , enzyme , biology , genetics , bioinformatics
The whole‐cell bioluminescent biosensor Pseudomonas putida F1G4 ( Pp F1G4), which contains a chromosomally‐based sep‐lux transcriptional fusion, was used as a tool for direct measurement of the bioavailability of hydrophobic organic compounds (HOCs) partitioned into surfactant micelles. The increased bioluminescent response of Pp F1G4 in micellar solutions (up to 10 times the critical micellar concentration) of Triton X‐100 and Brij 35 indicated higher intracellular concentrations of the test compounds, toluene, naphthalene, and phenanthrene, compared to control systems with no surfactants present. In contrast, Brij 30 caused a decrease in the bioluminescent response to the test compounds in single‐solute systems, without adversely affecting cell growth. The decrease in bioluminescent response in the presence of Brij 30 did not occur in the presence of multiple HOCs extracted into the surfactant solutions from crude oil and creosote. The effect of the micellar solutions on the toluene biodegradation rate was consistent with the bioluminescent response in single‐solute systems. None of the surfactants were toxic to Pp F1G4 at the doses employed in this study, and Pp F1G4 did not produce a bioluminescent response to the surfactants nor utilize them as growth substrates. TEM images suggest that the surfactants did not rupture the cell membranes. The results demonstrate that for Pseudomonas putida F1, nonionic surfactants such as Triton X‐100 and Brij 35, at doses between 2 and 10 CMC, may increase the bioavailability and direct uptake of micellar phase HOCs that are common pollutants at contaminated sites. Biotechnol. Bioeng. 2008;99: 86–98. © 2007 Wiley Periodicals, Inc.