pubmed-article:106267 | pubmed:abstractText | The azo reductase activity of a cell-free extract of Fusobacterium sp. 2 is characterized using trypan blue as a substrate. Either chemical reduction of this dye with sodium hydrosulfite or reduction by the cell-free extract produces a mutagenic product, o-tolidine. The o-tolidine is mutagenic in the Ames Salmonella/mammalian-microsome mutagenicity test when activated by a rat liver S9 preparation. | lld:pubmed |