...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Anaerobic growth of Methanosarcina acetivorans C2A on carbon monoxide: An unusual way of life for a methanogenic archaeon
【24h】

Anaerobic growth of Methanosarcina acetivorans C2A on carbon monoxide: An unusual way of life for a methanogenic archaeon

机译：乙酸甲烷单孢菌C2A在一氧化碳上的无氧生长：产甲烷古菌的一种不寻常的生活方式

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

All methanogenic Archaea examined to date rely on methanogenesis as their sole means of energy conservation. Among these are ones that use carbon monoxide as a growth substrate, producing methane via a pathway that involves hydrogen as an intermediate. To further examine the role of hydrogen in this process, we tested the ability of Methanosarcina acetivorans C2A, a metabolically versatile methanogen devoid of significant hydrogen metabolism, to use CO as a growth substrate. M. acetivorans grew on CO to high cell densities (approximate to1 x 10(8) per ml) with a doubling time of approximate to24 h. Surprisingly, acetate and formate, rather than methane, were the major metabolic end products as shown by C-13 NMR studies and enzymatic analysis of culture supernatants. Methane formation surpassed acetate/formate formation only when the cultures entered stationary growth phase, strongly suggesting that M. acetivorans conserves energy by means of this acetogenic and formigenic process. Resting cell experiments showed that methane production decreased linearly with increasing CO partial pressures, consistent with inhibition of methanogenesis by CO. Transposon-induced M. acetivorans mutants with lesions in the operon encoding phosphotransacetylase and acetate kinase failed to use either acetate or CO as growth substrates, indicating that these enzymes are required for both aceticlastic methanogenesis and carboxiclotrophic acetogenesis. These findings greatly extend our concept of energy conservation and metabolic versatility in the methanogenic Archaea.
机译：迄今为止，所有产甲烷的古细菌都依靠产甲烷作为其节能的唯一手段。其中有一些使用一氧化碳作为生长底物，通过涉及氢作为中间体的途径生产甲烷。为了进一步检查氢在此过程中的作用，我们测试了乙酸甲烷单孢甲烷球菌C2A（一种代谢通用的甲烷菌，缺乏明显的氢代谢）将CO用作生长底物的能力。乙酰丙腐球菌在CO上生长至高细胞密度（每毫升大约1 x 10（8）），而倍增时间大约为24小时。出乎意料的是，如C-13 NMR研究和培养物上清液的酶促分析所示，乙酸盐和甲酸而不是甲烷是主要的代谢终产物。仅当培养物进入稳定生长期时，甲烷的形成才超过乙酸盐/甲酸盐的形成，这强烈表明乙酸食甲烷分枝杆菌通过这种产乙酸和富甲酸的过程来节省能量。静息细胞实验表明，甲烷的产生随CO分压的增加呈线性下降，这与CO对甲烷生成的抑制作用是一致的。转座子诱导的食腐支原体突变体，其操纵子中编码磷酸转乙酰酶和乙酸激酶的损伤无法使用乙酸或CO作为生长底物，表明这些酶对于破弹性产甲烷和糖原性产乙酸都是必需的。这些发现大大扩展了我们在产甲烷古生菌中的能量守恒和代谢多样性的概念。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号