LIPID PEROXIDATION AND OTHER MEMBRANE DAMAGE PRODUCED IN Escherichia coli K1060 BY NEAR-UV RADIATION AND DEUTERIUM OXIDE

Abstract— With accumulating evidence that the membrane is an important site for near-UV inactivating events, we have investigated the effects of near-UV radiation on the unsaturated fatty acid auxotroph E. coli K1060 following incorporation into the membrane phospholipids of fatty acids with varying degrees of unsaturation. Sensitivity, lipid peroxidation and membrane damage, as determined by ⁸⁶Rb⁺ leakage, have been found to increase with increasing unsaturation in log-phase cells. Similar experiments carried out in D₂O also show an increase in sensitivity, lipid peroxidation and membrane damage, indicating that singlet oxygen may be responsible for such near-UV-radiation-induced damage