The effects of deuterium oxide on bacteria

Summary The growth of several strains of bacteria was inhibited by D₂O-media. The degree of inhibition was strain specific. The incorporation of 0.5% NaCl (w/v) to the D₂O-medium decreased the inhibition of growth. No adaptation to better growth in deuterium was obtained in any of the strains tested; however a deuterium resistant mutant was obtained from one strain. Two strains tested formed enlarged, distorted cells when grown for more than eight generations in D₂O-media. Cells grown in D₂O-media and washed and resuspended in H₂O-0.85% NaCl (w/v), were up to sixty times more sensitive to ultraviolet irradiation than control cells. Deuterium induces the occurrence of forward mutants in some strains. Many loci, but not all, showed an increase in the back-mutation rate over the spontaneous level, indicating some specificity of action by deuterium. Deuterated bases, obtained from a strain grown in D₂O-medium, did not induce any phenotypic or genotypic effects when supplied to specific baserequiring strains. The amout of deuterium incorporated into the bacteria may be related to the mutagenic effect induced. The genotypic and phenotypic effects induced by deuterium are probably the result of an overall isotope effect.With 2 Figures in the TextThe work reported here was supported by the Atomic Energy Commission research grant AT(30-1) 2184 to Dr.Stephen Zamenhof, Columbia University. This work was submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Faculty of Pure Science, Columbia University.I dedicate this paper to Prof.L. C. Dunn with thanks for his enthusiastic and inspiring instruction.