Open AccessConstruction and evaluation of a cea‐lacZ gene fusion for the detection of environmental mutagens and carcinogens
Author(s) -
Schumann W.,
Songür N.,
Miltenburger H.G.
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04777.x
Subject(s) - repressor lexa , lac operon , operon , plasmid , sos response , escherichia coli , salmonella , fusion gene , gene , biology , repressor , fusion protein , enterobacteriaceae , chemistry , genetics , microbiology and biotechnology , gene expression , bacteria , recombinant dna
The cea‐kil operon of the ColE1 plasmid is negatively regulated by the LexA‐repressor and therefore, it is under the control of SOS regulation. We constructed a gene fusion between the cea and lacZ genes. Expression of the translational fusion can be easily detected by monitoring the levels of β‐galactosidase. Since the whole detection system is plasmid‐based, it can be used in both Escherichia coli and Salmonella typhimurium strains. The SOS‐function‐inducing activities of 14 chemical mutagens were investigated in E. coli K12 and in two S. typhimurium Ames‐strains and compared with results obtained by the SOS‐chromotest and by the Umu‐test. To correct for the inhibitory effects of test chemicals on mRNA and/or protein synthesis, the level of the constitutive chloramphenicol acetyl transferase was assayed in parallel.