Mutagenicity in Salmonella typhimurium tester strains of XAD-2-ether extract, recovered from Katsura River water in Kyoto City, and its fractions.

The mutagenic activity of XAD-2-ether extracts recovered from Katsura River water at monthly intervals during September to December 1980 was tested on S. typhimurium TA1538, TA1535, TA98 and TA100. The extracts showed strong mutagenic activity towards TA1538 nd TA98, especially in the presence of S9 mix. They were more active to TA1538 than to TA98. Some of each of the XAD-2-ether extracts were pooled and separated into neutral, basic and acidic fractions, and their mutagenic activities were tested on TA1538 and TA98 to determine their contribution to the total mutagenic activity of the parent extract. The neutral fraction was responsible for most of the total mutagenic activity of the parent extract. Although the basic fraction was only 5.4% by weight of the parent extract, it was much more mutagenic than any other fraction. Its contribution to the total mutagenic activity was higher than the acidic fraction which was 30.5% by weight of the parent extract.