Effects of Deuterium Oxide on Streptococcus mutans and Pseudomonas aeruginosa

Abstract

A complex aggregation of microorganisms growing on a solid substrate is termed a biofilm and is considered to be an etiological agents. Pseudomonas aeruginosa and Streptococcus mutans are representative bacteria in such biofilms. It is well known that deuterium oxide (D 2 O) causes toxic effects on a number of biological systems. We investigated the effects of D 2 O on growth and biofilm formation of P. aeruginosa and S. mutans. These bacteria were incubated in medium containing D 2 O (100%, 75% or 0%) at 37°C for 24hr, 48 hr or 72hr. Growth of P. aeruginosa was inhibited by D 2 O within the first 48hr. However, after 72 hr, growth rate was seen to increase in the D 2 O-containing medium compared with in medium without D 2 O. In contrast, the growth of S. mutans in the D 2 O medium was inhibited within 72hr. The biofilm formation of P. aeruginosa was increased in the D 2 O medium. Biofilm formation of S. mutans in the D 2 O medium increased compared with in the medium without D 2 O, but this increase was only temporary in the case of P. aeruginosa. Compared to biofilm formation in 0% D 2 O medium marked as 100%, the biofilm formation rate of S. mutans in 75% D 2 O medium was 143% at 24hr, 146% at 48 hr and 130% at 72 hr. In other D 2 O concentration media biofilm formation was lower. In 100% D 2 O medium, biofilm formation rate decreased from 114% at 24hr to 56% at 72hr. The biofilm formation rate of P. aeruginosa in 100% D 2 O medium was 172% at 24hr, but decreased to 88% at 72hr. Biofilm formation of P. aeruginosa in 75% and 0% D 2 O media showed no significant difference. We consider that these results were due to stress or alteration in bacterial metabolisms.

Heavy Water Reduces GFP Expression in Prokaryotic Cell-Free Assays at the Translation Level While Stimulating Its Transcription

“… Figure 3(a) demonstrates an inhibitory effect of D 2 O on bacterial cell proliferation (growth rate) in agreement with results described elsewhere [19]. At the maximum D 2 O concentration of 98%, the cell growth rate was reduced to 65% of the value obtained for the control (i.e., M63 medium prepared solely with H 2 O).…”

“…While deuterium oxide at concentrations greater than 20% of body weight is highly toxic to animals [13], low concentrations of deuterium oxide seem to be harmless for animals and humans, and deuterated intraocular dyes are considered to be safe for clinical use [14]. Furthermore, several studies provided evidence for a significant reduction of human cancer cell lines growth in D 2 O culture medium [15], impairment of human tumor growth in animal models [16, 17], and generally a reduction of cellular proliferation at high deuterium concentrations in prokaryotic and eukaryotic cells [16, 18, 19]. …”

[2H26]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

“…Furthermore, deuterium kinetic isotope effects [18] may alter product distributions in branching biosynthetic pathways, which can be useful for their mechanistic interpretation [19]. At high deuterium concentrations such kinetic isotope effects slow down all metabolic processes, and consequently only very few reports on the cultivation of microorganisms in highly deuterated media are available from the literature [20–23]. For eukaryotes high deuterium oxide concentrations are even toxic, e.g., in mice intoxication with deuterium oxide resulted in degenerative defects on multiple organs [24].…”

Panagrolaimus superbus tolera troca total, homogênea e instantânea de sua matriz de H2O por D2O: estudos de sua aquaporina

“…Então, além mais curtas, as ligações de Deutério são consideradas também mais estáveis (fortes), de maior intensidade do que as ligações de Hidrogênio (KATZ, 1960). Além dos contrastes físicos, a literatura lista duas diferenças químicas entre H2O e D2O: o efeito isotópico de solvente (SIE ou 'solvent isotopic effect') e o efeito isotópico do deutério (DIE ou 'deuterium isotopic effect') (KATZ, 1960;KUSHNER, BAKER e DUNSTALL, 1999;HIRAI et al, 2010 CHELGREEN e CREAMER, 2004;GORYUNOV, 2006;KANG, HOKE e CRANE, 2006;HOHLEFELDER et al, 2013).…”

“…O DIE (isotópico) se caracteriza quando o deutério substitui o hidrogênio em biomoléculas (KUSHNER, BAKER e DUNSTALL, 1999;CLELAND, 2004;KANG, HOKE e CRANE, 2006;HIRAI et al, 2010;HOHLEFELDER et al, 2013). A força de ligação do deutério com elementos como o Carbono, Nitrogênio e Oxigênio é mais forte do que a ligação do hidrogênio (KATZ, 1960;KUSHNER, BAKER e DUNSTALL, 1999 (KATZ, 1960;THOMSON, 1960;KATZ et al, 1962;HUGHES, HILDRETH e BECKER, 1964;SAMIS, BAIRD e MASSIE, 1973;HIRAI et al, 2010;MINAMOTO, WADA e SHIMIZU, 2012;HAMMEL et al, 2013;HOHLEFELDER et al, 2013;KIRKINA et al, 2014).…”