Abstract
It is well known that Salmonella typhimurium TA102 is a useful tester strain in detecting mutagenicity of chemicals which are not or weakly detected by the other tester strains in Ames test. However, this strain gives higher spontaneous revertant colonies, and somewhat large difference of mutagenicity among laboratories. As a part of studies in getting a reliable test protocol for this strain in preincubation method, we studied the effect of growth culture conditions on the mutagenicity of bleomycin and methyl methanesulfonate in the absence of S9 mix and 2-aminoanthracene in the presence of S9 mix.
Highest mutagenicity for these chemicals was observed in the test using 6 hour cultured strain, although 9-16 hour cultured strains have usually been used in Ames test. The mutagenicity was 4 and 12 times higher than those by 9 hour and 16 hour cultured strains for bleomycin, and 2 and 4 times higher than 9 hour and 16 hour cultured strains for methyl methanesulfonate. The mutagenicity of 2-aminoanthracene was nearly same with that by 9 hour cultured strain and slightly higher than that by 16 hour cultured strain. On 6 hour cultured strain, mutagenicity of bleomycin was affected by the interval from the end of growth culture to the beginning of the test, but mutagenicities of methyl methanesulfonate and 2-aminoanthracene were not.
These results suggest that mutagenicity test using Salmonella typhimurium TA102 should be done quickly using strain obtained by growing culture for 6 hour.
