<?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>Cindy Umberger</dc:contributor>
  <dc:contributor>Charles W. Culbertson</dc:contributor>
  <dc:contributor>Richard L. Smith</dc:contributor>
  <dc:creator>Ronald S. Oremland</dc:creator>
  <dc:date>1984</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The acetylene block technique was employed to study denitrification in intertidal estuarine sediments. Addition of nitrate to sediment slurries stimulated denitrification. During the dry season, sediment-slurry denitrification rates displayed Michaelis-Menten kinetics, and ambient NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;&lt;span&gt;&amp;nbsp;+ NO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;&lt;span&gt;&amp;nbsp;concentrations (&amp;le;26 &amp;mu;M) were below the 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;(50 &amp;mu;M) for nitrate. During the rainy season, when ambient NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;&lt;span&gt;&amp;nbsp;+ NO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;&lt;span&gt;&amp;nbsp;concentrations were higher (37 to 89 &amp;mu;M), an accurate estimate of the&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;could not be obtained. Endogenous denitrification activity was confined to the upper 3 cm of the sediment column. However, the addition of nitrate to deeper sediments demonstrated immediate N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O production, and potential activity existed at all depths sampled (the deepest was 15 cm). Loss of N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O in the presence of C&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;H&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;was sometimes observed during these short-term sediment incubations. Experiments with sediment slurries and washed cell suspensions of a marine pseudomonad confirmed that this N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O loss was caused by incomplete blockage of N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O reductase by C&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;H&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;at low nitrate concentrations. Areal estimates of denitrification (in the absence of added nitrate) ranged from 0.8 to 1.2 &amp;mu;mol of N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;sup&gt;&amp;minus;2&lt;/sup&gt;&lt;span&gt;&amp;nbsp;h&lt;/span&gt;&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;(for undisturbed sediments) to 17 to 280 &amp;mu;mol of N&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;sup&gt;&amp;minus;2&lt;/sup&gt;&lt;span&gt;&amp;nbsp;h&lt;/span&gt;&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;(for shaken sediment slurries).&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1128/aem.47.5.1106-1112.1984</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Society for Microbiology</dc:publisher>
  <dc:title>Denitrification in San Francisco Bay intertidal sediments</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>