Establishment of New Strains of S. Typhimurium Highly Sensitive to Nitroarenes and Aromatic Amines: TA98 and TA100 Substrains with Rich Nitroreductase or Acetyltransferase Activities

Abstract

Nitroreductase and acetyltransferase genes of S. typhimurium TA1538 are cloned into pBR322 (see Watanabe et al., Biochem. Biophys. Res. Commun., 147 974–979 (1987)). The plasmids (pYG216, which contains a nitroreductase gene, and pYG219, which contains an acetyltransferase gene) were introduced into TA98 and TA100. TA98(pYG216), TA98(pYG219), TA100(pYG216) and TA100(pYG219) were named as YG1021, YG1024, YG1026 and YG1029, respectively. YG1021 and YG1026 had nitrofurazone-reductase activity about 50 times higher than the original strain, TA1538(pBR322), and were highly sensitive to 2-nitrofluorene (2-NF), 1-nitropyrene (1-NP) and 2-nitronaphthalene (2-NN)(Mutat. Res., in press (1989)). YG1024 and YG1029 had isoniazid-, 2-aminofluorene-N-acetyltransferase and N-hydroxy-Glu-P-1-0-acetyltransferase activities 100 times higher than TA1538(pBR322), and were highly sensitive to 2-NF, 1-NP, 1,8-dinitropyrene, 2-NN, Glu-P-1(+S9) and 2-aminoanthracene(+S9). These newly established strains are recommended to use for the detection of a small amount of nitroarenes and aromatic amines in the environment, and also for the estimation of metabolic pathway of chemical mutagens.