RUI: Thermophilic Ammonia-Oxidzing Archaea: Physiology, Genomics and Role in Nitrogen Cycling at High Temperature.

智力上的优点近年来，我们对氮循环的理解有了重大的修正。新的生物过程，如厌氧氨氧化的发现，以及认识到关键的代谢过程，如氨氧化更广泛地分布在现存的生物体和更广泛的栖息地范围，迫使我们重新评估近世纪的数据收集和地球化学建模。此外，生物体之间介导氮循环关键过程的基因组分析也迫使我们重新审视我们对这些代谢途径最初是如何发展的假设。最近发现的嗜热硝化古菌扩大了我们对能够支持基于氨氧化的代谢的生物和栖息地的认识。随着其他能够转化含氮化合物的嗜热微生物的发现，这些结果表明在高温环境中存在复杂的，可能是古老的氮循环。了解有助于这种高温氮循环的生物体和代谢过程可能会告知这些营养循环最初是如何演变的。本项目的主要目的是详细研究嗜热氨氧化古菌Nitrosocaldus yellowstonii氨氧化途径的生理和生物化学。旧金山弗朗西斯科州立大学的研究人员将使用生理学、生物化学、分子和基因组方法的组合来更好地了解N. yellowstonii和氨氧化代谢的演变。更广泛的影响这些研究的结果预计将显着推进我们的氨氧化代谢的演变和高温环境中氮循环的微生物学的理解。然而，该项目的一个重要方面是培训和促进来自传统上在科学领域代表性不足的群体的年轻科学家。该项目将在旧金山弗朗西斯科州立大学进行，这是一所大型综合性公立大学，拥有大量代表性不足的少数民族学生。该项目将通过PI（URM本人）和高级实验室人员的指导，培养一名URM博士后研究员，两名研究生和1-3名本科生。PI将把这些研究纳入他的本科和研究生教学，以激发学生对微生物生态学，进化和基因组学的兴趣。

Intellectual MeritRecent years have seen a significant revision of our understanding of the nitrogen cycle. The discovery of new biological processes such as anaerobic ammonia oxidation, and the recognition that key metabolic processes like ammonia oxidation are more broadly distributed among extant organisms and across broader habitat ranges have forced us to reevaluate nearly a century of data collection and biogeochemical modeling. Furthermore, genomic analyses between organisms mediating key processes in the nitrogen cycle also oblige us to revisit our assumptions of how these metabolic pathways first developed. The recent discovery of a thermophilic nitrifying archaeon has expanded our view of the organisms and habitats capable of supporting ammonia oxidation based metabolism. With the discovery of other thermophilic microorganism capable of transforming nitrogen compounds, these results suggest the existence of a complex, possibly ancient nitrogen cycle in high temperature environments. Understanding the organisms and metabolic processes that contribute this high temperature nitrogen cycle may inform how these nutrient cycles first evolved. The principal objective of this project is a detailed investigation of the physiology and biochemistry of the pathway for ammonia oxidation in the thermophilic ammonia oxidizing archaeon Nitrosocaldus yellowstonii. Researchers at San Francisco State University will use a combination of physiological, biochemical, molecular and genomic approaches to better understand the biology of N. yellowstonii and the evolution of ammonia-oxidation based metabolism.Broader ImpactsThe results of these studies are expected to significantly advance our understanding of the evolution of ammonia-oxidation based metabolism and of the microbiology of nitrogen cycling in high temperature environments. However, an important aspect of this project is the training and promotion of young scientists from groups traditionally underrepresented in Science. This project will be conducted at San Francisco State University, a large, comprehensive, public university with a large pool of underrepresented minority (URM) students. The project will train one URM postdoctoral fellow, two graduate students and 1-3 undergraduates through mentoring by the PI (a URM himself) and senior laboratory personnel. The PI will incorporate these studies into his undergraduate and graduate teaching to stimulate student interest in microbial ecology, evolution, and genomics.