Induction and mutagenesis of prophage λ in Escherichiacoli K12 by metabolites of aflatoxin B 1

Abstract

Like most carcinogens, aflatoxin B 1 must be activated by mammalian microsomal enzymes to give rise to compounds active on bacteria. These compounds act as inducers of E. coli K12 (λ)_at a high efficiency, whereas unmodified aflatoxin B 1 has no effect. Moreover, metabolites of aflatoxin B 1 have a mutagenic action on phage λ, as shown by the appearance of clear plaque mutants. We propose the hypothesis that the same derivatives is responsible for carcinogenesis of liver cells by aflatoxin B 1. Therefore, our system provides a simple way of measuring in vitro, in the same assay, the mutagenic and inducing activities of compounds to which the cells are permeable, thereby detecting potentially carcinogenic agents.