Scholarlink

<p>Anaerobic methanotrophic archaea mitigate methane emissions in anoxic environments as key members of the biological methane filter. Despite their ecological significance, physiology of anaerobic methanotrophs remains poorly understood. Here, we demonstrate that the freshwater methanotroph ‘<i>Candidatus</i> Methanoperedens BLZ2’ prefers carbon monoxide (CO) over methane as an electron donor. Without respiratory nitrate, CO oxidation led to acetogenesis and methanogenesis with rates comparable to methane oxidation with nitrate. The circularized genome of ‘<i>Ca</i>. M. BLZ2’ encodes six Ni-dependent carbon monoxide dehydrogenases (CODHs<b>)</b>, three of which were highly expressed. Furthermore, we identified a 156-kbp mobile genetic element carrying central metabolic gene clusters, including two additional, highly expressed CODHs. CODH genes were widespread in <i>Methanoperedenaceae</i> and showed diverse evolutionary affiliations, including <i>Methanocomedenaceae</i> anaerobic methanotrophs and bacterial lineages. These findings highlight CO metabolism and genome plasticity in anaerobic methanotrophs challenging their classification as obligate methanotrophs and their ecological role in anoxic carbon cycling.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Carbon monoxide metabolism in freshwater anaerobic methanotrophic archaea

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月14日

查看全文
  • Reinier A. Egas,
  • Heyu Lin,
  • Andy O. Leu,
  • Gene W. Tyson,
  • Simon J. McIlroy,
  • Cornelia U. Welte

摘要

Anaerobic methanotrophic archaea mitigate methane emissions in anoxic environments as key members of the biological methane filter. Despite their ecological significance, physiology of anaerobic methanotrophs remains poorly understood. Here, we demonstrate that the freshwater methanotroph ‘Candidatus Methanoperedens BLZ2’ prefers carbon monoxide (CO) over methane as an electron donor. Without respiratory nitrate, CO oxidation led to acetogenesis and methanogenesis with rates comparable to methane oxidation with nitrate. The circularized genome of ‘Ca. M. BLZ2’ encodes six Ni-dependent carbon monoxide dehydrogenases (CODHs), three of which were highly expressed. Furthermore, we identified a 156-kbp mobile genetic element carrying central metabolic gene clusters, including two additional, highly expressed CODHs. CODH genes were widespread in Methanoperedenaceae and showed diverse evolutionary affiliations, including Methanocomedenaceae anaerobic methanotrophs and bacterial lineages. These findings highlight CO metabolism and genome plasticity in anaerobic methanotrophs challenging their classification as obligate methanotrophs and their ecological role in anoxic carbon cycling.