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弗里森（密歇根州立大学）主要合作者：A。威廉卢瑟福和马丁巴克（帝国理工学院伦敦）氮是最常见的限制营养植物生长。虽然多种细菌和古细菌已经进化出使用固氮酶将大气中的二氮气体固定为生物可利用的氨的能力，但生物固氮在农业中缺乏广泛的适用性。首先，该过程在能量上是昂贵的。其次，所有研究充分的固氮酶都被氧抑制，需要特殊的结构才能有效地发挥作用。然而，在德国，有一个关于氧不敏感固氮酶系统的单一报道，该系统分离自一种在燃烧的炭火上发现的热自养链霉菌细菌。这种超氧化物依赖性固氮酶仅被部分表征，并且该菌株不再可用。本项目旨在培养原始菌株，以及从类似的恶劣环境中寻找可能含有相关固氮酶系统的其他菌株。特别是，该项目将针对一氧化碳水平升高的煤层火和活火山;按照原始的分离方法，菌株将在高温下培养，并富含一氧化碳和二氧化碳。一旦鉴定，这些菌株将确定其基因组序列并注释基因。分离它们的土壤也将被测序，以确定这些恶劣环境中存在的所有可培养和不可培养微生物的聚合元基因组。然后，该项目将寻求确定这些生物体中固氮酶系统的生化和生理特性，并尝试将耐氧固氮酶转移到其他微生物中，用于未来的生物技术应用。该项目有可能极大地改变生物固氮研究，并最终导致植物自身固氮的工程。该项目将通过三名博士后和一名研究生的参与促进培训。项目成果和信息将通过公开讲座和播客在美国（http：//variationselectioninheritance.podbean.com/）和英国（http：//wwwf.imperial.ac.uk/imedia/itunes_collections/view/special-lectures）传播。此外，还将维持一个项目博客，详细介绍实地收集旅行和研究结果。表征菌株可通过ATCC：http://www.atcc.org/获得。注释的基因组和元基因组序列将通过NCBI Genbank：http：//www.ncbi.nlm.nih.gov/genbank/获得;元基因组数据也将贡献给地球微生物组计划：http://www.earthmicrobiome.org。质量受控的序列读数将被保存到NCBI序列读数档案馆：http://www.ncbi.nlm.nih.gov/Traces/sra/中，并在保存时可通过计算机获得。