ANTIMUTAGENIC EFFECT OF CULTURE LIQUID OBTAINED IN PROPIONIC-ACID FERMENTATION

It was shown that, in the process of growth, propionic acid bacteria excrete substances which exert an antimutagenic effect with respect to mutagenesis induced by 4-nitroquinoline N-oxide in Salmonella typhimurium TA100. The substances act as desmutagens. The antimutagenic activity positively correlated with the dose of the antimutagen and the duration of its preincubation with the mutagen. The activity was the highest in a filtrate of a young (24 - 48-h) Propionibacterium shermanii culture. Substances possessing antimutagenic activity were produced during growth in a medium containing glucose, lactose, or lactate. The antimutagenic factor is dialyzable and thermostable and is not of a peptide nature.