Oxygen-Tolerant Nitrogenase

耐氧固氮酶

• 批准号: 1331218
• 负责人: Maren Friesen
• 金额: $ 59.91万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1331218&HistoricalAwards=false
• 关键词: Oxygen; Tolerant; Nitrogenase

PI: Maren Friesen (Michigan State University)Key Collaborators: A. William Rutherford and Martin Buck (Imperial College London)Nitrogen is most often the limiting nutrient to plant growth. While multiple bacteria and archaea have evolved the ability to fix atmospheric dinitrogen gas into biologically available ammonia using the nitrogenase enzyme, biological nitrogen fixation lacks wide applicability in agriculture. First, the process is energetically expensive. Second, all well-studied nitrogenase enzymes are inhibited by oxygen and require special structures to function effectively. However, there is a singular report of an oxygen insensitive nitrogenase system, isolated from a Streptomyces thermoautotrophicus bacterium found above burning charcoal fires in Germany. This superoxide dependent nitrogenase was only partially characterized and the strain is no longer available. The present project seeks to culture the original strain, as well as search for additional strains from similarly harsh environments that may harbor related nitrogenase systems. In particular, the project will target coal-seam fires and active volcanoes that have elevated levels of carbon monoxide; following the original isolation methods, strains will be cultivated under high temperatures with a carbon monoxide and carbon dioxide enriched atmosphere. Once identified, these strains will have their genome sequences determined and genes annotated. The soils from which they are isolated will also be sequenced to determine the aggregate meta-genome of all culturable and non-culturable microbes present in these harsh environments. The project will then seek to determine the biochemical and physiological properties of the nitrogenase systems in these organisms and attempt to transfer the oxygen-tolerant nitrogenase into other microbes for future biotechnology applications. The project has the potential to dramatically alter biological nitrogen fixation research and could ultimately lead to the engineering of plants that fix their own nitrogen. This project will contribute to training through the involvement of three post-docs and one graduate student. Project outcomes and information will be disseminated through public lectures and through podcasts, both in the US (http://variationselectioninheritance.podbean.com/) and the UK (http://wwwf.imperial.ac.uk/imedia/itunes_collections/view/special-lectures). In addition, a project blog will be maintained that will detail field collection trips and research findings. Characterized strains will be available via the ATCC: http://www.atcc.org/. Annotated genome and meta-genome sequences will be available through NCBI Genbank: http://www.ncbi.nlm.nih.gov/genbank/; the meta-genome data will also be contributed to the Earth Microbiome Project: http://www.earthmicrobiome.org. Quality controlled sequence reads will be deposited into the NCBI Sequence Read Archive: http://www.ncbi.nlm.nih.gov/Traces/sra/ and made publically available upon deposition.

PI：Maren Friesen（密歇根州立大学）主要合作者：A。William Rutherford和Martin Buck（伦敦帝国学院）氮通常是植物生长的限制营养素。虽然多种细菌和古细菌已经发展出使用氮酶固定大气二氮气气体将大气中的二氮气体固定到生物学上可用的氨的能力，但生物氮固定在农业中缺乏广泛的适用性。首先，这个过程在能量上很昂贵。其次，所有研究良好的氮酶都受到氧气抑制，需要特殊的结构才能有效发挥作用。然而，有一个单一的报道，即从德国燃烧的木炭火灾上方发现的氧气不敏感的氮气系统，该氧气不敏感的氮气系统是从链霉菌链霉菌中分离出来的。该超氧化物依赖性氮酶仅部分表征，并且不再可用。本项目旨在培养原始菌株，并从可能具有相关氮酶系统的类似恶劣环境中寻找其他菌株。特别是，该项目将针对煤缝火和一氧化碳水平升高的活火山。按照原始的隔离方法，将在高温下以一氧化碳和二氧化碳富含大气的气氛培养菌株。一旦确定，这些菌株将确定其基因组序列并注释基因。从与之分离的土壤也将进行测序，以确定这些恶劣环境中存在的所有可培养和不可培养的微生物的总元基因组。然后，该项目将寻求确定这些生物体中氮酶系统的生化和生理特性，并试图将耐氧氮酶转移到其他微生物中以进行未来的生物技术应用。该项目有可能极大地改变生物氮固定研究，并最终导致固定自己的氮的工程。该项目将通过参与三个后docs和一名研究生的参与来有助于培训。项目成果和信息将通过公开演讲和播客进行分散，包括在美国（http://variationselectioninheritance.podbean.com/）和英国（http://wwwwwf.imperial.ac.ac.ac.ac.ac.uk/imedia/imedia/ithes_collections/thunes_collections/view/view/special-special-speial-special-special-special-special-lecters）。此外，还将维护一个项目博客，以详细介绍现场收集旅行和研究结果。特征菌株将通过ATCC：http：//www.atcc.org/提供。注释的基因组和元基因组序列将通过NCBI GenBank提供：http：//www.ncbi.nlm.nih.gov/genbank/;元基因组数据还将为地球微生物组项目做出贡献：http：//www.earthmicrobiome.org。质量控制的序列读取将沉积到NCBI序列读取存档中：http：//www.ncbi.nlm.nih.gov/traces/sra/，并在沉积后公开提供。