小島久弥さんが、淡水湖沼の嫌気的な湖水から新属の脱窒硫黄酸化細菌を発見。至適温度が２２℃で、元素状硫黄やチオ硫酸塩の酸化能を有する。硫黄酸化の際に、電子受容体として硝酸塩を利用し、窒素にまで変換する。つまり、湖沼生態系からの窒素除去に寄与していると考えられる。<o:p></o:p>
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その新規微生物名は、Sulfuricella denitrificans 。詳細は、”International Journal of Systematic and Evolutionary Microbiology”で（オンラインで公開）。<o:p></o:p>
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Hisaya Kojima and Manabu Fukui.
Sulfuricella
denitrificans gen. nov., sp. nov., a novel
sulfur-oxidizing autotroph isolated from a freshwater lake. International
Journal of Systematic and Evolutionary Microbiology.
<link href="file://localhost/Users/MFukui/Library/Caches/TemporaryItems/msoclip/0/clip_filelist.xml" rel="File-List" /> <style> &amp;amp;amp;amp;lt;!-- /* Font Definitions */ @font-face {amp;amp;amp;amp;amp;quot;ＭＳ 明朝&amp;amp;amp;amp;quot;; panose-1:2 2 6 9 4 2 5 8 3 4; mso-font-charset:78; mso-generic-mso-font-pitch:variable; mso-font-signature:1 0 16778247 0 131072 0;} @font-face {panose-1:2 4 6 4 5 5 5 2 3 4; mso-font-charset:0; mso-generic-mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {amp;amp;amp;amp;amp;quot;\@ＭＳ 明朝&amp;amp;amp;amp;quot;; panose-1:2 2 6 9 4 2 5 8 3 4; mso-font-charset:78; mso-generic-mso-font-pitch:variable; mso-font-signature:1 0 16778247 0 131072 0;} @font-face {amp;amp;amp;amp;amp;quot;ヒラギノ角ゴ Pro W3&amp;amp;amp;amp;quot;; panose-1:2 11 3 0 0 0 0 0 0 0; mso-font-alt:&amp;amp;amp;amp;quot;ヒラギノ角ゴ Pro W3&amp;amp;amp;amp;quot;; mso-font-charset:78; mso-generic-mso-font-pitch:variable; mso-font-signature:1 0 16778247 0 131072 0;} @font-face {amp;amp;amp;amp;amp;quot;\@ヒラギノ角ゴ Pro W3&amp;amp;amp;amp;quot;; panose-1:2 11 3 0 0 0 0 0 0 0; mso-font-charset:78; mso-generic-mso-font-pitch:variable; mso-font-signature:1 0 16778247 0 131072 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:&amp;amp;amp;amp;quot;&amp;amp;amp;amp;quot;; margin:0mm; margin-bottom:.0001pt; text-align:justify; text-justify:inter-ideograph; mso-pagination:none; font-size:12.0pt; amp;amp;amp;amp;amp;quot;Times New Roman&amp;amp;amp;amp;quot;; mso-ascii-mso-ascii-theme-font:minor-latin; mso-fareast-amp;amp;amp;amp;amp;quot;ＭＳ 明朝&amp;amp;amp;amp;quot;; mso-fareast-theme-font:minor-fareast; mso-hansi-mso-hansi-theme-font:minor-latin; mso-bidi-amp;amp;amp;amp;amp;quot;Times New Roman&amp;amp;amp;amp;quot;; mso-bidi-theme-font:minor-bidi; mso-font-kerning:1.0pt;} /* Page Definitions */ @page {mso-page-border-surround-header:no; mso-page-border-surround-footer:no;} @page Section1 {size:612.0pt 792.0pt; margin:99.25pt 30.0mm 30.0mm 30.0mm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&amp;amp;amp;amp;gt; </style> Abstract. A novel facultatively anaerobic sulfur-oxidizing bacterium, strain skB26T was isolated from anoxic water of a freshwater lake in Japan. The cells were rod-shaped, motile, and Gram-negative. As sole energy source, the isolate oxidized elemental sulfur and thiosulfate to sulfate. The strain skB26T was microaerobic, and also could utilize nitrate as electron acceptor, reducing it to nitrogen. Growth was observed at temperature lower than 28°C, and the optimum growth was observed at 22°C. The range of pH for growth was 6.0-9.0, and the optimum pH was 7.5-8.0. The optimum growth of the isolate was observed in the medium without NaCl, and no growth was observed in the medium containing NaCl more than 220 mM. The G+C content of genomic DNA was around 59 mol%. Phylogenetic analysis based on 16S rRNA gene indicated that the strain was member of the class Betaproteobacteria, and the closest cultivated relative was 'Thiobacillus plumbophilus', with the sequence similarity of 93%. Phylogenetic analyses were also performed on genes involved in sulfur oxidation, inorganic carbon fixation, and nitrate respiration. On the basis of its phylogenetic and phenotypic properties, the strain skB26T (=NBRC 105220T =DSM 22764T) is proposed as type strain of a new species of a novel genus, Sulfuricella denitrificans gen. nov., sp. nov.
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