{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T03:26:33Z","timestamp":1785813993757,"version":"3.56.0"},"reference-count":67,"publisher":"American Society for Microbiology","issue":"3","license":[{"start":{"date-parts":[[2018,1,17]],"date-time":"2018-01-17T00:00:00Z","timestamp":1516147200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2018,2,1]],"date-time":"2018-02-01T00:00:00Z","timestamp":1517443200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/100006132","name":"DOE | Office of Science","doi-asserted-by":"publisher","award":["DE-AC05-00OR22725"],"award-info":[{"award-number":["DE-AC05-00OR22725"]}],"id":[{"id":"10.13039\/100006132","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Appl Environ Microbiol"],"published-print":{"date-parts":[[2018,2]]},"abstract":"ABSTRACT<\/jats:title>\n \n Neurotoxic methylmercury (MeHg) is produced by anaerobic\n Bacteria<\/jats:named-content>\n and\n Archaea<\/jats:named-content>\n possessing the genes\n hgcAB<\/jats:italic>\n , but it is unknown how organic substrate and electron acceptor availability impacts the distribution and abundance of these organisms. We evaluated the impact of organic substrate amendments on mercury (Hg) methylation rates, microbial community structure, and the distribution of\n \n hgcAB\n +<\/jats:sup>\n <\/jats:italic>\n microbes with sediments. Sediment slurries were amended with short-chain fatty acids, alcohols, or a polysaccharide. Minimal increases in MeHg were observed following lactate, ethanol, and methanol amendments, while a significant decrease (\u223c70%) was observed with cellobiose incubations. Postincubation, microbial diversity was assessed via 16S rRNA amplicon sequencing. The presence of\n \n hgcAB\n +<\/jats:sup>\n <\/jats:italic>\n organisms was assessed with a broad-range degenerate PCR primer set for both genes, while the presence of microbes in each of the three dominant clades of methylators (\n Deltaproteobacteria<\/jats:named-content>\n ,\n Firmicutes<\/jats:named-content>\n , and methanogenic\n Archaea<\/jats:named-content>\n ) was measured with clade-specific degenerate\n hgcA<\/jats:italic>\n quantitative PCR (qPCR) primer sets. The predominant microorganisms in unamended sediments consisted of\n Proteobacteria<\/jats:named-content>\n ,\n Firmicutes<\/jats:named-content>\n ,\n Bacteroidetes<\/jats:named-content>\n , and\n Actinobacteria<\/jats:named-content>\n . Clade-specific qPCR identified\n \n hgcA\n +<\/jats:sup>\n <\/jats:italic>\n Deltaproteobacteria<\/jats:named-content>\n and\n Archaea<\/jats:named-content>\n in all sites but failed to detect\n hgcA<\/jats:italic>\n +<\/jats:sup>\n Firmicutes<\/jats:named-content>\n . Cellobiose shifted the communities in all samples to \u223c90% non-\n hgcAB<\/jats:italic>\n -containing\n Firmicutes<\/jats:named-content>\n (mainly\n Bacillus<\/jats:named-content>\n spp. and\n Clostridium<\/jats:named-content>\n spp.). These results suggest that either expression of\n hgcAB<\/jats:italic>\n is downregulated or, more likely given the lack of 16S rRNA gene presence after cellobiose incubation, Hg-methylating organisms are largely outcompeted by cellobiose degraders or degradation products of cellobiose. These results represent a step toward understanding and exploring simple methodologies for controlling MeHg production in the environment.\n <\/jats:p>\n \n IMPORTANCE<\/jats:bold>\n Methylmercury (MeHg) is a neurotoxin produced by microorganisms that bioacummulates in the food web and poses a serious health risk to humans. Currently, the impact that organic substrate or electron acceptor availability has on the mercury (Hg)-methylating microorganisms is unclear. To study this, we set up microcosm experiments exposed to different organic substrates and electron acceptors and assayed for Hg methylation rates, for microbial community structure, and for distribution of Hg methylators. The sediment and groundwater was collected from East Fork Poplar Creek in Oak Ridge, TN. Amendment with cellobiose (a lignocellulosic degradation by-product) led to a drastic decrease in the Hg methylation rate compared to that in an unamended control, with an associated shift in the microbial community to mostly nonmethylating\n Firmicutes<\/jats:named-content>\n . This, along with previous Hg-methylating microorganism identification methods, will be important for identifying strategies to control MeHg production and inform future remediation strategies.\n <\/jats:p>","DOI":"10.1128\/aem.01049-17","type":"journal-article","created":{"date-parts":[[2017,11,17]],"date-time":"2017-11-17T16:20:25Z","timestamp":1510935625000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":46,"title":["Carbon Amendments Alter Microbial Community Structure and Net Mercury Methylation Potential in Sediments"],"prefix":"10.1128","volume":"84","author":[{"given":"Geoff A.","family":"Christensen","sequence":"first","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anil C.","family":"Somenahally","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"},{"name":"Department of Soil and Crop Sciences, Texas A&M University, Overton, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James G.","family":"Moberly","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"},{"name":"Department of Chemical and Materials Engineering, University of Idaho, Moscow, Idaho, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carrie M.","family":"Miller","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"},{"name":"Department of Biology, Troy University, Troy, Alabama, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew J.","family":"King","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cynthia C.","family":"Gilmour","sequence":"additional","affiliation":[{"name":"Smithsonian Environmental Research Center, Edgewater, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven D.","family":"Brown","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mircea","family":"Podar","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Craig C.","family":"Brandt","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Scott C.","family":"Brooks","sequence":"additional","affiliation":[{"name":"Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anthony V.","family":"Palumbo","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Judy D.","family":"Wall","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of Missouri, Columbia, Missouri, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4469-6391","authenticated-orcid":false,"given":"Dwayne A.","family":"Elias","sequence":"additional","affiliation":[{"name":"Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1021\/es304370g"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1021\/es403075t"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.1500675"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1021\/es0524144"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.scitotenv.2013.09.098"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.apgeochem.2007.12.020"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.72.1.457-464.2006"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1021\/es2033718"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1021\/es2010072"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01556-13"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01271-16"},{"key":"e_1_3_3_13_2","volume-title":"ORNL\/TM-2009\/231","author":"Southworth GR","year":"2010","unstructured":"Southworth GR, Greeley MS, Peterson MJ, Lowe K, Ketelle RH. 2010. Sources of mercury to East Fork Poplar Creek downstream from the Y-12 national security complex: inventories and export rates. ORNL\/TM-2009\/231. Oak Ridge National Laboratory, Oak Ridge, TN."},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF01189744"},{"key":"e_1_3_3_15_2","first-page":"262","volume-title":"Biogeochemistry of environmentally important trace elements","author":"Benoit JM","year":"2003","unstructured":"Benoit JM, Gilmour CC, Heyes A, Mason RP, Miller CL. 2003. Geochemical and biological controls over methylmercury production and degradation in aquatic ecosystems, p 262\u2013297. In Braids OC, Cai Y(ed), Biogeochemistry of environmentally important trace elements. American Chemical Society, Washington, DC."},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/es9808200"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1002\/etc.5620181004"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.48.6.1203-1207.1984"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.53.2.261-265.1987"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1016\/0269-7491(91)90031-Q"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1023\/A:1005972708616"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1021\/es034528q"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1021\/es049096d"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.1021\/es0262939"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00170-11"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1088727"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.envpol.2013.08.030"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.envpol.2010.09.009"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1017\/S1466046604000249"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0045-6535(02)00249-7"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0045-6535(99)00562-7"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.3354\/ame01563"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00248-010-9734-2"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01715-10"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1021\/es960318k"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1111\/1462-2920.12086"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.42.3.413-420.1981"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1128\/MMBR.66.3.506-577.2002"},{"key":"e_1_3_3_39_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.33.2.289-297.1977"},{"key":"e_1_3_3_40_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1230667"},{"key":"e_1_3_3_41_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-2836(05)80360-2"},{"key":"e_1_3_3_42_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00443275"},{"key":"e_1_3_3_43_2","doi-asserted-by":"publisher","DOI":"10.1128\/br.41.2.514-541.1977"},{"key":"e_1_3_3_44_2","doi-asserted-by":"publisher","DOI":"10.3390\/ijms9071342"},{"key":"e_1_3_3_45_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00248-002-1060-x"},{"key":"e_1_3_3_46_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.64.6.1987-1990.1998"},{"key":"e_1_3_3_47_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11356-015-4273-5"},{"key":"e_1_3_3_48_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.scitotenv.2016.03.005"},{"key":"e_1_3_3_49_2","doi-asserted-by":"publisher","DOI":"10.1039\/C5EM00174A"},{"key":"e_1_3_3_50_2","doi-asserted-by":"publisher","DOI":"10.1021\/es3000933"},{"key":"e_1_3_3_51_2","first-page":"28","article-title":"The generalization of \u201cStudent's\u201d problem when several different population variances are involved","volume":"34","author":"Welch BL","year":"1947","unstructured":"Welch BL. 1947. The generalization of \u201cStudent's\u201d problem when several different population variances are involved. Biometrika 34:28\u201335.","journal-title":"Biometrika"},{"key":"e_1_3_3_52_2","first-page":"65","article-title":"A simple sequentially rejective multiple test procedure","volume":"6","author":"Holm S","year":"1979","unstructured":"Holm S. 1979. A simple sequentially rejective multiple test procedure. Scand J Stat 6:65\u201370.","journal-title":"Scand J Stat"},{"key":"e_1_3_3_53_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chemosphere.2015.05.083"},{"key":"e_1_3_3_54_2","doi-asserted-by":"publisher","DOI":"10.1007\/s002160050432"},{"key":"e_1_3_3_55_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0041295"},{"key":"e_1_3_3_56_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0102826"},{"key":"e_1_3_3_57_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01541-09"},{"key":"e_1_3_3_58_2","doi-asserted-by":"publisher","DOI":"10.1038\/nmeth.f.303"},{"key":"e_1_3_3_59_2","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2105-12-38"},{"key":"e_1_3_3_60_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkt1244"},{"key":"e_1_3_3_61_2","unstructured":"Oksanen J Blanchet FG Kindt R Legendre P Minchin PR O'Hara RB Simpson GL Solymos P Henry M Stevens H Wagner H. 2016. vegan: community ecology package. R package 2.3-5."},{"key":"e_1_3_3_62_2","volume-title":"R: a language and environment for statistical computing","author":"R Core Team","year":"2016","unstructured":"R Core Team. 2016. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria."},{"key":"e_1_3_3_63_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkh340"},{"key":"e_1_3_3_64_2","doi-asserted-by":"publisher","DOI":"10.1093\/molbev\/msp077"},{"key":"e_1_3_3_65_2","first-page":"32","article-title":"A new method for non-parametric multivariate analysis of variance","volume":"26","author":"Anderson MJ","year":"2001","unstructured":"Anderson MJ. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecol 26:32\u201346.","journal-title":"Austral Ecol"},{"key":"e_1_3_3_66_2","doi-asserted-by":"publisher","DOI":"10.1890\/0012-9658(2001)082(0290:FMMTCD)2.0.CO;2"},{"key":"e_1_3_3_67_2","doi-asserted-by":"publisher","DOI":"10.1186\/gb-2007-8-2-r19"},{"key":"e_1_3_3_68_2","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/29.9.e45"}],"container-title":["Applied and Environmental Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AEM.01049-17","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AEM.01049-17","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,23]],"date-time":"2022-02-23T18:50:24Z","timestamp":1645642224000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AEM.01049-17"}},"subtitle":[],"editor":[{"given":"Shuang-Jiang","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2018,2]]},"references-count":67,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2018,2]]}},"alternative-id":["10.1128\/AEM.01049-17"],"URL":"https:\/\/doi.org\/10.1128\/aem.01049-17","relation":{},"ISSN":["0099-2240","1098-5336"],"issn-type":[{"value":"0099-2240","type":"print"},{"value":"1098-5336","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,2]]},"assertion":[{"value":"2017-05-09","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2017-09-28","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-01-17","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e01049-17"}}