Deuterium-depletion has no significant impact on the mutation rate of Escherichia coli, deuterium abundance therefore has a probabilistic, not deterministic effect on spontaneous mutagenesis

Deuterium (D), the second most abundant isotope of hydrogen is present in natural waters at an approximate concentration 145–155 ppm (ca. 1.5E-4 atom/atom). D known to influence various biological processes due its physical and chemical properties, which significantly differ from those hydrogen. For example, increasing D-concentration >1000-fold above abundance has been shown increase frequency genetic mutations several species. An interesting deterministic hypothesis, formulated with intent explaining mechanism D-mutagenicity based on calculation that theoretical probability base pairs comprise two adjacent D-bridges instead H-bridges 2.3E-8, equal mutation rate certain To experimentally challenge this infer mutagenicity concentrations, we investigated effect a nearly 100-fold reduction bacterial rate. Using fluctuation tests, measured three Escherichia coli genes ( cycA , ackA galK ) media containing either <2 or 150 concentrations. Out 15 pair-wise analyses, nine indicated significant decrease, while marked mutation/culture value upon D-depletion. Overall, growth D-depleted minimal medium led geometric mean 0.663-fold (95% confidence interval: 0.483–0.911) change This falls nowhere near expected 10,000-fold reduction, indicating our systems, formation point not deterministic. In addition, combined results did display statistically value, mutant The potential mutagenic concentrations E . therefore below limit detection using methods.