The Effect of Protectors onSerratia Marcescensduring Anaerobic X-irradiation

Abstract

The effect of concentration on the ability to protect bacteria under anoxic conditions against x-ray damage has been studied for five different substances. Glycerol had no effect at concentrations of 10 mM and below, but at high concentrations (1 to 5 M) it was the most effective protector. Dimethyl sulphoxide, like glycerol, had no effect below 10 mM; it was more effective than glycerol at intermediate concentration and less effective at high concentrations. Cysteine protected at very low concentrations but the effect fell rapidly on raising the concentration beyond 0·5 M. Mercapto ethanol behaved as though it combined the protector effect of glycerol and cysteine. Ascorbic acid behaved like cysteine at low concentrations and dimethyl sulphoxide at high concentrations.