Bioactivation of promutagens by the unicellular green alga Chlamydomonas reinhardtii.

The aromatic amine 2-aminofluorene (2-AF) was activated by the intact Chlamydomonas reinhardtii cells to a mutagen that exhibited toxic and mutagenic effects comparable to those of the direct-acting mutagen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). There were different responses of the wildtype and repair-deficient strains to the toxic and mutagenic effect of 2-AF. The recombination repair plays a major role in repair of damages induced in the C. reinhardtii DNA by the aromatic amine promutagen 2-AF and the direct-acting mutagen MNNG. The 2-AF activation has also been analyzed by algal cells/microbe coincubation assay. This new assay is used in addition to animal microsome-metabolizing system (S9 fraction) and plant cell/microbe coincubation assay. This additional system is suitable for detection of environmental promutagens and their conversion to mutagens, mainly in aquatic environments.