Chitosan is derived by deacetylation of chitin, a major component of the shells of crustacea such as crabs and shrimps. In this experiment using the Ames test, there was antimutagenic effect by the water-soluble chito...Chitosan is derived by deacetylation of chitin, a major component of the shells of crustacea such as crabs and shrimps. In this experiment using the Ames test, there was antimutagenic effect by the water-soluble chitosan that dissolved in hard water （CHW）. The Ames test was performed using Salmonella typhimurium TA98 and TA100. For the antimutagenic test, and the desmutagenic and bioantimutagenic tests, Trp-P-2, 2AA and AF-2 were used as mutagens. Tests for spontaneous mutation rate without mutagens were performed using S. typhimurium TA98 and TA100. When several concentrations of CHW were directly added to Minimal Glucose Plates, there were no changes in the number of His＋ revertants of TA98 and TA100. In desmutagenic and bioantimutagenic tests, the number of His^＋ revertants of TA98 and TA100 decreased. In the test for spontaneous mutation rate, the number of His＋ revertants of TA98 and TA 100 decreased slightly. When a concentration of CHW was added to examine antimutagenic effects, there was no change in the viable cell count of TA98 and TA100. From these results, AF-2 that is a direct mutagen may combine with CHW, and that may also be carrying out the inactivation. CHW possibly acts directly on the DNA by decreasing the rate at which mutation is caused to the strain＇s promutagens, Trp-P-2 and 2AA. This is evident from the decreased spontaneous mutation rate without a decreased viable cell count.展开更多
文摘Chitosan is derived by deacetylation of chitin, a major component of the shells of crustacea such as crabs and shrimps. In this experiment using the Ames test, there was antimutagenic effect by the water-soluble chitosan that dissolved in hard water （CHW）. The Ames test was performed using Salmonella typhimurium TA98 and TA100. For the antimutagenic test, and the desmutagenic and bioantimutagenic tests, Trp-P-2, 2AA and AF-2 were used as mutagens. Tests for spontaneous mutation rate without mutagens were performed using S. typhimurium TA98 and TA100. When several concentrations of CHW were directly added to Minimal Glucose Plates, there were no changes in the number of His＋ revertants of TA98 and TA100. In desmutagenic and bioantimutagenic tests, the number of His^＋ revertants of TA98 and TA100 decreased. In the test for spontaneous mutation rate, the number of His＋ revertants of TA98 and TA 100 decreased slightly. When a concentration of CHW was added to examine antimutagenic effects, there was no change in the viable cell count of TA98 and TA100. From these results, AF-2 that is a direct mutagen may combine with CHW, and that may also be carrying out the inactivation. CHW possibly acts directly on the DNA by decreasing the rate at which mutation is caused to the strain＇s promutagens, Trp-P-2 and 2AA. This is evident from the decreased spontaneous mutation rate without a decreased viable cell count.
