naa a22 4500 510752454 CHVBK 20180411083109.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1007/s11270-012-1399-7 doi (NATIONALLICENCE)springer-10.1007/s11270-012-1399-7 Influences of Zero-Valent Sulfur on Mercury Methylation in Bacterial Cocultures [Elektronische Daten] [Rita Kampalath, Chu-Ching Lin, Jennifer Jay] The speciation of mercury (Hg) is a major determinant of its methylation rate by sulfate-reducing bacteria (SRB), considered the primary methylators. Under anoxic conditions, sulfur (S) cycling may have a significant influence on Hg complexation and methylation, by influencing both SRB activity and the pool of available reduced S ligands, as the presence of zero-valent sulfur (S(0)) in sulfidic water results in the formation of polysulfides. While SRB frequently coexist with S-oxidizing bacteria in natural environments, the effect that these organisms may have on methylation by SRB is not understood. In this study, we investigate the role of S(0) in methylation by SRB monocultures and cocultures with phototrophic green or purple S-oxidizing bacteria. In the coculture experiments, the presence of S-oxidizers was found to increase Hg methylation rates, apparently by maintaining favorable chemical speciation in the environment. The measured Hg methylation rates were in accord with predictions based on geochemical modeling of speciation. In SRB monoculture experiments conducted in the presence and absence of S(0), the data showed that at limited total Hg, the presence of polysulfides resulted in decreased Hg methylation, presumably by causing a decrease in the most bioavailable Hg-sulfide complexes. These results indicate that models of Hg speciation and methylation in the environment should include a detailed investigation of S redox speciation. Springer Science+Business Media Dordrecht, 2012 Mercury methylation nationallicence Polysulfides nationallicence SRB nationallicence Phototrophic S-oxidizers nationallicence Cocultures nationallicence Bioavailability nationallicence Kampalath Rita Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut Lin Chu-Ching Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut Jay Jennifer Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut Water, Air, & Soil Pollution Springer Netherlands 224/2(2013-02-01), 1-14 0049-6979 224:2<1 2013 224 11270 https://doi.org/10.1007/s11270-012-1399-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-012-1399-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kampalath Rita Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut NATIONALLICENCE 700 1- Lin Chu-Ching Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut NATIONALLICENCE 700 1- Jay Jennifer Department of Civil and Environmental Engineering, UCLA, 5732H Boelter Hall, 420 Westwood Plaza, 90095, Los Angeles, CA, USA aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/2(2013-02-01), 1-14 0049-6979 224:2<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer