<?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.K. Varner</dc:contributor>
  <dc:contributor>P.M. Crill</dc:contributor>
  <dc:contributor>Ronald S. Oremland</dc:contributor>
  <dc:creator>K.D. Goodwin</dc:creator>
  <dc:date>2001</dc:date>
  <dc:description>&lt;div id="abstract-1" class="section abstract" data-gtm-vis-first-on-screen-6041348_20="1964" data-gtm-vis-total-visible-time-6041348_20="100" data-gtm-vis-has-fired-6041348_20="1"&gt;&lt;p id="p-2"&gt;Pure cultures of methylotrophs and methanotrophs are known to oxidize methyl bromide (MeBr); however, their ability to oxidize tropospheric concentrations (parts per trillion by volume [pptv]) has not been tested. Methylotrophs and methanotrophs were able to consume MeBr provided at levels that mimicked the tropospheric mixing ratio of MeBr (12 pptv) at equilibrium with surface waters (≈2 pM). Kinetic investigations using picomolar concentrations of MeBr in a continuously stirred tank reactor (CSTR) were performed using strain IMB-1 and&lt;i&gt;Leisingeria methylohalidivorans&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;strain MB2&lt;sup&gt;T&lt;/sup&gt;— terrestrial and marine methylotrophs capable of halorespiration. First-order uptake of MeBr with no indication of threshold was observed for both strains. Strain MB2&lt;sup&gt;T&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;displayed saturation kinetics in batch experiments using micromolar MeBr concentrations, with an apparent&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;&lt;i&gt;s&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;of 2.4 μM MeBr and a&lt;i&gt;V&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sub&gt;max&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;of 1.6 nmol h&lt;sup&gt;−1&lt;/sup&gt;(10&lt;sup&gt;6&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;cells)&lt;sup&gt;−1&lt;/sup&gt;. Apparent first-order degradation rate constants measured with the CSTR were consistent with kinetic parameters determined in batch experiments, which used 35- to 1 × 10&lt;sup&gt;7&lt;/sup&gt;-fold-higher MeBr concentrations.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Ruegeria algicola&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;(a phylogenetic relative of strain MB2&lt;sup&gt;T&lt;/sup&gt;), the common heterotrophs&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Escherichia coli&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and&lt;i&gt;Bacillus pumilus&lt;/i&gt;, and a toluene oxidizer,&lt;i&gt;Pseudomonas mendocina&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;KR1, were also tested. These bacteria showed no significant consumption of 12 pptv MeBr; thus, the ability to consume ambient mixing ratios of MeBr was limited to C&lt;sub&gt;1&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;compound-oxidizing bacteria in this study. Aerobic C&lt;sub&gt;1&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;bacteria may provide model organisms for the biological oxidation of tropospheric MeBr in soils and waters.&lt;/p&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1128/AEM.67.12.5437-5443.2001</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>ASM</dc:publisher>
  <dc:title>Consumption of tropospheric levels of methyl bromide by C1 compound-utilizing bacteria and comparison to saturation kinetics</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>