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Title: Enzyme biosynthesis in bacteria as a basis for toxicity testing

Miscellaneous ·
OSTI ID:6518156

An assay based on the inhibition of {beta}-galactosidase biosynthesis was compared to a similar assay based on the inhibition of {beta}-galactosidase activity. In both test, Escherichia coli were induced to synthesize {beta}-galactosidase by exposure to isopropyl-{beta}-thiogalactoside (IPTG). The induction step preceded contact of the cells with toxic chemicals in the enzyme activity assay, whereas in the enzyme biosynthesis test, IPTG was added following contact of cells with the toxicant. Relative sensitivity was judged on the basis of responses to heavy metals and organic toxicants of environmental importance. Comparison of these results to median inhibitory concentration data (IC50s) achieved with other microbial systems, Daphnia bioassay, and fish bioassay indicate that the enzyme activity test was sensitive to heavy metals, but was insensitive to organic toxicants. The test based on inhibition of {beta}-galactosidase biosynthesis was sensitive to both heavy metals and organics.

Research Organization:
Florida Univ., Gainesville, FL (USA)
OSTI ID:
6518156
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English