Effect of bifidobacteria on nitrites and nitrosamines

The effects of six different bifidobacteria strains were studied on two procarcinogens: nitrite and nitrosamines. Growth of bifidobacteria was not affected by nitrite concentrations below 50 μmol 1^-1. At nitrite concentrations greater than 2000 μmol 1^-1, total growth inhibition was observed. Nitrite elimination by a non-enzymic mechanism was noted for six strains of bifidobacteria. Acids produced by the bacteria seem to be involved in nitrite elimination. Nitrosamines tested had no effect on growth of bifidobacteria. Only one strain ( Bifidobacterium longum BB 536) was able to metabolize nitrosamines by an intracellular mechanism.