Antimutagenicity of Plant Origin Lactic Acid Bacteria Isolated from Rice and Processed Rice Products

Abstract

Nine strains of plant origin lactic acid bacteria were isolated from rice and processed rice products to examine their antimutagenic effect. Tested Lactic acid bacteria were six strains of Lactobacillus casei subsp. casei and three strains of L. plantarum. Used mutagens were 3-amino-1, 4-dimethyl-5H-pyrido (4, 3-b) indole (Trp-P1), 3-amino-1-methyl-5H-pyrido (4, 3-b) indole (Trp-P2), 2-aminoanthracene (2-AA) and N-methyl-N' nitro-N-nitrosoguanidine (MNNG). Antimutagenic activity on living and killed cells of lactic acid bacteria were measured using Escherichia coli WP2uvrA. All strains showed antimutagenic activities against Trp-P1, Trp-P2 and 2-AA. The activity against Trp-P1 was higherthan the other mutagens. Living and killed cells of lactic acid bacteria showed similar activity against Trp-P1 and Trp-P2. Four strains of killed cells of L. casei subsp. casei had higher activity than the living cells against 2-AA. Only living cells of L. casei subsp. casei had antimutagenic activities against MNNG. This result was similar case to our previous report using 4-nitro-quinoline-1-oxide.