在一个无氧甲性转化协会中对氧化还原活性细胞外聚合物质的表征
Xueqin Zhang1, Jing Zhao2, Dirk V Erler3
1Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia.
Journal of environmental management
|June 20, 2024
概括
甲 (AOM) 的无氧氧氧化使古生物产生富含蛋白质的细胞外聚合物质 (EPS). 这些EPS含有c型细胞染色体,使电子转移和减轻银毒性.
科学领域:
- 微生物学 微生物学
- 生物地质化学生物地质化学
- 环境科学 环境科学
背景情况:
- 甲无氧氧化 (AOM) 是全球碳循环中的一个关键的微生物过程.
- 厌氧甲类古生物 (ANME) 调解AOM,但它们的生理学仍然不太清楚.
- 细胞外聚合物 (EPS) 是微生物群落的关键组成部分,但它们在ANME中的作用在很大程度上是未知的.
研究的目的:
- 研究来自ANME丰富培养的EPS的生化和氧化还原活性特性.
- 阐明EPS在AOM过程中的生理作用.
- 描述ANME衍生的EPS的组成和功能组.
主要方法:
- 使用了一个由"Candidatus Methanoperedens nitroreducens"主导的财团.
- 使用福里埃变换红外光谱 (FTIR) 和X射线光电子光谱 (XPS) 进行了EPS的特征化.
- 通过血红反应性染色和光谱分析证实了EPS中c型细胞染色体的存在和功能,并使用Ag+减小试验测试了细胞外电子转移 (EET) 能力.
主要成果:
- 在ANME EPS矩阵中,蛋白质与多糖的比例很高 (~8),并且由蛋白质相关的功能组占主导地位.
- 在蛋白质丰富的EPS中确定了C型细胞染色体,赋予了电活性特性.
- 通过EPS介导的细胞外电子转移将Ag+降低到金属Ag,EPS矩阵中的纳米粒子形成减少了细胞内银的毒性.
结论:
- 这项研究提供了对无氧甲类联盟的EPS的第一个生化见解.
- 这些发现揭示了EPS在ANME中的新生理作用,特别是在细胞外电子转移和金属排毒中.
- 蛋白质主导的电活性EPS矩阵对于ANME在潜在的金属暴露环境中的生存和功能至关重要.
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