在细胞外电子转移中,分泌类的作用
1Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA. dkn@gps.caltech.edu
Nature
|May 16, 2000
概括
细菌可以使用矿物质进行呼吸,但它们如何将电子转移到不溶性化合物如铁氧化物是不清楚的. 这项研究表明,分泌的menaquinone分子在Shewanella putrefaciens中促进了这一过程.
科学领域:
- 微生物学 微生物学
- 环境科学 环境科学
- 生物化学 生物化学
背景情况:
- 细菌呼吸利用各种化合物作为终端电子受体,包括不溶性矿物质.
- 与可溶性受体相比,对不溶性化合物 (如铁氧化物) 的电子传输的了解很少.
- 性物质在无氧环境中起到电子受体和铁氧化物运输的作用.
研究的目的:
- 为了研究细菌呼吸在湿性物质上的机制.
- 为了识别在Shewanella putrefaciens中呼吸不溶性电子受体必不可少的基因.
- 阐明小分子在微生物电子转移到矿物中的作用.
主要方法:
- 基因查以识别Shewanella putrefaciens突变的突变物,这些突变物不能在性物质上呼吸.
- 基因干扰分析以确定影响气物质呼吸的突变.
- 补充试验使用分泌的分子来恢复突变者的呼吸功能.
主要成果:
- 缺乏性物质呼吸能力的突变者在参与menaquinone生物合成的基因中出现了干扰.
- 野生类型的Shewanella putrefaciens将一种与menaquinone相关的分子释放到介质中.
- 这种分泌的分子恢复了突变者在气物质上呼吸的能力.
结论:
- menaquinone生物合成对于Shewanella putrefaciens在性物质上呼吸至关重要.
- 微生物分泌的能可以调解电子转移到不溶性氧化剂,包括矿物质.
- 这一发现扩大了我们对微生物电子运输和生物地球化学循环的理解.
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