<?xml version='1.0' encoding='utf-8'?>
<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>R.S. Oremland</dc:contributor>
  <dc:creator>N.A. Steinberg</dc:creator>
  <dc:date>1990</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;We measured potential rates of bacterial dissimilatory reduction of&amp;nbsp;&lt;/span&gt;&lt;sup&gt;75&lt;/sup&gt;&lt;span&gt;SeO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;to&amp;nbsp;&lt;/span&gt;&lt;sup&gt;75&lt;/sup&gt;&lt;span&gt;Se&lt;/span&gt;&lt;sup&gt;0&lt;/sup&gt;&lt;span&gt;&amp;nbsp;in a diversity of sediment types, with salinities ranging from freshwater (salinity = 1 g/liter) to hypersaline (salinity = 320 g/liter and with pH values ranging from 7.1 to 9.8. Significant biological selenate reduction occurred in all samples with salinities from 1 to 250 g/liter but not in samples with a salinity of 320 g/liter. Potential selenate reduction rates (25 nmol of SeO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;per ml of sediment added with isotope) ranged from 0.07 to 22 μmol of SeO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;reduced liter&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;h&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt;. Activity followed Michaelis-Menten kinetics in relation to SeO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;concentration (&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;m&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;of selenate = 7.9 to 720 μM). There was no linear correlation between potential rates of SeO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;reduction and salinity, pH, concentrations of total Se, porosity, or organic carbon in the sediments. However, potential selenate reduction was correlated with apparent&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;m&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;for selenate and with potential rates of denitrification (&lt;/span&gt;&lt;i&gt;r&lt;/i&gt;&lt;span&gt;&amp;nbsp;= 0.92 and 0.81, respectively). NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;&lt;span&gt;, NO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;&lt;span&gt;, MoO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;, and WO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;inhibited selenate reduction activity to different extents in sediments from both Hunter Drain and Massie Slough, Nev. Sulfate partially inhibited activity in sediment from freshwater (salinity = 1 g/liter) Massie Slough samples but not from the saline (salinity = 60 g/liter) Hunter Drain samples. We conclude that dissimilatory selenate reduction in sediments is widespread in nature. In addition, in situ selenate reduction is a first-order reaction, because the ambient concentrations of selenium oxyanions in the sediments were orders of magnitude less than their&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;m&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;s.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1128/aem.56.11.3550-3557.1990</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Society for Microbiology</dc:publisher>
  <dc:title>Dissimilatory selenate reduction potentials in a diversity of sediment types</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>