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Researchers from Oregon State University Report on Findings in Nitrosomonas europaea (Influence of Water Hardness on Silver Ion and Silver...

August 22, 2014



Researchers from Oregon State University Report on Findings in Nitrosomonas europaea (Influence of Water Hardness on Silver Ion and Silver Nanoparticle Fate and Toxicity Toward Nitrosomonas europaea)

By a News Reporter-Staff News Editor at Ecology, Environment & Conservation -- Investigators publish new report on Proteobacteria. According to news reporting from Corvallis, Oregon, by VerticalNews journalists, research stated, "This study investigated the influence of water hardness (Mg2+ and Ca2+) on the fate and toxicity of 20 nm citrate silver nanoparticles (AgNPs) and Ag+ toward Nitrosomonas europaea, a model ammonia-oxidizing bacterium. Nitrification inhibition of N. europaea by 1 ppm AgNPs and 0.5 ppm Ag+ was reduced from 80% and 83%, respectively, in the absence of Mg2+ to 2% and 33%, respectively, in the presence of 730 mu M Mg2+."

The news correspondents obtained a quote from the research from Oregon State University, "Introduction of Mg2+ resulted in the rapid aggregation of the AgNP suspensions and reduced the 3 h Ag+ dissolution rates from 30%, in the absence of Mg2+, to 9%, in the presence of 730 mu M Mg2+. Reduced AgNP dissolution rates resulted in decreased concentrations of silver that were found adsorbed to N. europaea cells. Increasing AgNP concentrations in the presence of Mg2+ increased the observed inhibition of nitrification, but was always less than what was observed in the absence of Mg2+. The presence of Mg2+ also reduced the adsorption of Ag+ to cells, possibly due to multiple mechanisms, including a reduction in the negative surface charge of the N. europaea membrane and a competition between Mg2+ and Ag+ for membrane binding sites and transport into the cells. Ca2+ demonstrated similar protection mechanisms, as Ag+ toxicity was reduced and AgNP suspensions aggregated and decreased their dissolution rates."

According to the news reporters, the research concluded: "These results indicate that the toxicity of Ag+ and AgNPs to nitrifying bacteria in wastewater treatment would be less pronounced in systems with hard water."

For more information on this research see: Influence of Water Hardness on Silver Ion and Silver Nanoparticle Fate and Toxicity Toward Nitrosomonas europaea. Environmental Engineering Science, 2014;31(7):403-409. Environmental Engineering Science can be contacted at: Mary Ann Liebert, Inc, 140 Huguenot Street, 3RD Fl, New Rochelle, NY 10801, USA. (Mary Ann Liebert, Inc. - www.liebertpub.com; Environmental Engineering Science - www.liebertpub.com/overview/environmental-engineering-science/15/)

Our news journalists report that additional information may be obtained by contacting J.W. Anderson, Oregon State University, Sch Chem Biol & Environm Engn, Corvallis, OR 97331, United States. Additional authors for this research include L. Semprini and T.S. Radniecki.

Keywords for this news article include: Oregon, Corvallis, United States, Proteobacteria, Nitrosomonadaceae, Nitrosomonas europaea, Gram-Negative Bacteria, North and Central America, Gram-Negative Aerobic Bacteria, Gram-Negative Aerobic Rods and Cocci

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Ecology, Environment & Conservation


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