Antimutagenicity of Milk Cultured with Lactic Acid Bacteria Against N-Methyl-N'-Nitro-N-Nitrosoguanidine

¹ Technical Research Laboratory, Takanashi Milk Produds Co., Ltd. Yokohama, Kanagawa-ken 241, Japan
² Faculty of Agriculture, Shinshu University, Minamiminowa-mura, Nagano-ken 399-45, Japan

The antimutagenic effect of cultured milk using 71 strains of lactic acid bacteria belonging to the genus Lactobacillus, Streptococcus, Lactococcus, and Bifidobacterium on the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine was investigated in vitro using Salmonella typhimurium TA 100 as an indicator bacterium. Each cultwed milk sample displayed its characteristic antimutagenic effect on the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine. The milk cultured with Lactobacillus acidophilus LA 106 (LA2) showed the highest inhibition of 77% against the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine among the strains tested. Changes in the antimutagenic effect of the milk cultured by Lb. acidophilus LA 106 (LA2) during incubation were also examined using N-methyl-N'-nitro-N-nitrosoguanidine as a mutagen.

Key Words: antimutagenicity • lactic acid bacteria • N-methyl-N'-nitro-N-nitrosoguanidine

Submitted on August 2, 1991
Accepted on November 12, 1991