Growth and morphology of Streptococcus bovis and of mixed rumen bacteria in the presence of aflatoxin B1, in vitro.

The metabolism of aflatoxin B1 to other fluorescent compounds was studied in rumen organisms. No fluorescent metabolites were found by chromatographic procedures which separate aflatoxin B1 from them. Rumen bacteria (mixtures and Streptococcus bovis) incubated with aflatoxin B1 grew in long chains whereas cells in control cultures were mainly doublets with some short chains. Growth of mixed rumen bacteria and Streptococcus bovis cultures was inhibited by aflatoxin B1 as measured by change in optical density and by incorporation of [carbon-14] adenine into nucleic acids.