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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Daniel Ritter</dc:contributor>
  <dc:contributor>Jennifer McIntosh</dc:contributor>
  <dc:contributor>Elliott P. Barnhart</dc:contributor>
  <dc:contributor>Alfred B. Cunningham</dc:contributor>
  <dc:contributor>David Vinson</dc:contributor>
  <dc:contributor>William H. Orem</dc:contributor>
  <dc:contributor>Matthew W. Fields</dc:contributor>
  <dc:creator>Hannah Schweitzer</dc:creator>
  <dc:date>2019</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Competition between microbial&amp;nbsp;sulfate&amp;nbsp;reduction and&amp;nbsp;methanogenesis&amp;nbsp;drives cycling of fossil carbon and generation of CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;in&amp;nbsp;sedimentary basins. However, little is understood about the fundamental relationship between subsurface aqueous&amp;nbsp;geochemistry&amp;nbsp;and&amp;nbsp;microbiology&amp;nbsp;that drives these processes. Here we relate elemental and isotopic geochemistry of coal-associated water and gas to the&amp;nbsp;microbial community&amp;nbsp;composition from wells in two different&amp;nbsp;coal beds&amp;nbsp;across CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;gradients (Powder River Basin, Montana, USA). Areas with high CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;concentrations generally have higher&amp;nbsp;alkalinity&amp;nbsp;and δ&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;span&gt;C-DIC values, little to no SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;, and greater conversion of coal-biodegradable organics to CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;(based on δ&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;span&gt;C-CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;and δ&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;&lt;span&gt;C-CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;values). Wells with SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;concentrations from 2 to 10 mM had bacterial populations dominated by several different sulfate-reducing bacteria and archaea that were mostly novel and unclassified. In contrast, in wells with SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;concentrations &amp;lt;1 mM, the sequences were dominated by presumptive syntrophic bacteria as well as archaeal&amp;nbsp;&lt;/span&gt;&lt;i&gt;Methanosarcinales&lt;/i&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;i&gt;Methanomicrobiales&lt;/i&gt;&lt;span&gt;. The presence of sequences indicative of these bacteria in low SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;methanogenic wells may suggest a syntrophic role in coal&amp;nbsp;biodegradation&amp;nbsp;and/or the generation of methanogenic substrates from intermediate organic compounds. Archaeal sequences were observed in all sampled zones, with an enrichment of sequences indicative of&amp;nbsp;methanogens&amp;nbsp;in low SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;zones and unclassified sequences in high SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;zones. However, sequences indicative of&amp;nbsp;&lt;/span&gt;&lt;i&gt;Methanomassiliicoccales&lt;/i&gt;&lt;span&gt;&amp;nbsp;were enriched in intermediate SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;zones and suggest tolerance to SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;and/or alternative metabolisms in the presence of SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;. Moreover, sequences indicative of methylotrophic methanogens were more prevalent in an intermediate SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;and CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;well and results suggest an important role for methylotrophic methanogens in critical&amp;nbsp;zone transitions. The presented results demonstrate&amp;nbsp;&lt;/span&gt;&lt;i&gt;in situ&lt;/i&gt;&lt;span&gt;&amp;nbsp;changes in bacterial and archaeal&amp;nbsp;population distributions&amp;nbsp;along a SO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;gradient associated with recalcitrant,&amp;nbsp;organic carbon&amp;nbsp;that is biodegraded and converted to CO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and/or CH&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/j.gca.2018.11.009</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Changes in microbial communities and associated water and gas geochemistry across a sulfate gradient in coal beds: Powder River Basin, USA</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>