ARSENIC AND OLD LIFE: NOVEL GEOBIOCHEMISTRY OF ARSENIC IN BIOLOGICAL SYSTEMS

砷与旧生命：生物系统中砷的新型地球生物化学

• 批准号: 8362382
• 负责人: FELISA L WOLFE-SIMON
• 金额: $ 0.14万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362382
• 关键词: Arsenates; Arsenic; Cells; Coupled; Data; Funding; Gammaproteobacteria; Grant; Growth; Life; Mass Spectrum Analysis; Measures; Mono-S; National Center for Research Resources; Nutrient; Organism; Plasma; Principal Investigator; Radiation; Radiolabeled; Recombinant DNA; Research; Research Infrastructure; Resources; Source; United States National Aeronautics and Space Administration; United States National Institutes of Health; Water; base; biological systems; cost; high risk; inorganic phosphate; interest; lead arsenate; member; novel; radiotracer; structural biology; uptake

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The focus of our study, that is the identification and characterization of a living example of arsenic-based life, is certainly a high risk but exceedingly interesting study as funded by the NASA NAI. Thus far we have used the arsenic-rich, hypersaline and highly alkaline waters of Mono Lake, CA to hunt for such an unusual organism. Our current status is that we have enriched for, isolated and identified (by 16s rDNA) a member of the gamma-Proteobacteria that are known to bioaccumulate arsenic. We confirmed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) that under growth conditions in which ONLY 5 mM arsenate was amended to the medium and NO phosphate was added this strain has a As/P ratio of almost 7; however this strain can also grow with phosphate only and phosphate combined with arsenate leading to the reassuring As/P ratios of 0.001 and 0.010, respectively. In addition, we are currently measuring the uptake of radiolabeled 73As arsenate to confirm the rate of uptake under a variety of anionic nutrient conditions, but our data indicate that developing a comprehensive picture of the intracellular arsenic content and speciation of cells grown with and without arsenate or phosphate would greatly strengthen our story.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 我们研究的重点是对砷基生命活体实例的识别和表征，这无疑是一项由 NASA NAI 资助的高风险但非常有趣的研究。到目前为止，我们已经利用加利福尼亚州莫诺湖富含砷的高盐度和高碱性水域来寻找这种不寻常的生物。我们目前的状况是，我们已经富集、分离并鉴定（通过 16s rDNA）已知能生物富集砷的 γ-变形菌门成员。我们通过电感耦合等离子体质谱 (ICP-MS) 证实，在培养基中仅添加 5 mM 砷酸盐且不添加磷酸盐的生长条件下，该菌株的 As/P 比几乎为 7；然而，该菌株也可以只用磷酸盐生长，也可以在磷酸盐与砷酸盐结合的情况下生长，从而分别产生令人放心的 0.001 和 0.010 的 As/P 比。此外，我们目前正在测量放射性标记的 73As 砷酸盐的摄取，以确认在各种阴离子营养条件下的摄取率，但我们的数据表明，全面了解细胞内砷含量和在有或没有砷酸盐或磷酸盐的情况下生长的细胞的形态将大大加强我们的故事。