Managing the Nitrogen economy of bacteria

管理细菌的氮经济

• 批准号: BB/N003608/1
• 负责人: Martin Buck
• 金额: $ 456.47万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FN003608%2F1
• 关键词: Managing; Nitrogen; economy; bacteria

We plan to address how the supply of one key nutrient for plant growth - nitrogen in a form that can be taken up by plants(i.e. ammonia) - can be supplied by soil dwelling bacteria. A lack of nitrogen supply to plants frequently limits their growth,and the use of chemically produced nitrogen fertilizers threatens the environment and is energetically expensive toproduce. Hence alternative methods to supply fixed nitrogen that are not dependent on fossil fuels or the application ofchemicals to the soil are desirable. We plan to investigate how the nitrogen economy of simple soil dwelling bacteria isestablished through the network of control systems operating to achieve optimal levels of ammonia within cells, and tomodify these control systems to then allow the export of ammonia or amino acids to the soil and hence to plants. Ammoniawill be produced by the action of the bacterial nitrogen fixing enzyme nitrogenase, and we will work out how the bacterialcell regulates this metabolic process in order to maximize its own resource use efficiency. This knowledge will allow us torewire the regulatory control for the purpose of enhancing agricultural productivity.To date some simple first pass attempts have been made to exploit bacterial ammonia export for plant growth, and somewhat surprisingly these one offs show promise in that plant growth is enhanced in a manner suggesting reduced nitrogen from the bacteria is becoming available to support plant growth.Hence successfully refining ammonia export by bacteria holds great promise.Our work requires that we accurately quantify various key small molecules and proteins used to determine the cellsnitrogen economy, and produce a scheme whereby we can intervene and create a situation where some of the nitrogenasederived ammonia is excreted from the bacterial cells to the outside without greatly sacrificing the growth and fitness of thenitrogen fixing bacteria. To do so we will use methodologies which capture the various players of the control systems inaction, allowing us to work out where the major points of regulation occur and how they might be modified to gain anammonia export function without losing the fitness of the organism. This approach requires that we combine experimentswith modelling of the nitrogen control schemes, and also deploy synthetic biology tools to produce new master generegulator proteins which will allow us to capture the control of the entire complex networks of genes needed for the cellsmanagement of its nitrogen economy. By combining these approaches with knowledge and parallel study of how soil dwelling bacteriaestablish close associations with plant roots and are competitive , and in particular how they gain carbon as an energy source from plants, weexpect to be able to in a sustainable way improve nitrogen supply to plants in order to improve crop yields. In addition, weplan to utilize the knowledge and understanding that is gained in this project to also develop renewable biotechnologicalprocesses for industrial production of nitrogen containing chemicals that is driven entirely by solar energy.

我们计划解决如何供应植物生长的一种关键营养素-可以被植物吸收的氮（即氨）-可以由土壤中的细菌提供。缺乏氮的供应往往限制了植物的生长，而使用化学生产的氮肥会威胁环境，而且生产成本高昂。因此，替代方法来提供固定氮，不依赖于化石燃料或应用化学品的土壤是可取的。我们计划研究简单的土壤寄居细菌如何通过控制系统网络建立氮经济，以实现细胞内氨的最佳水平，并修改这些控制系统，然后允许氨或氨基酸出口到土壤，从而到植物。氨将通过细菌固氮酶的作用产生，我们将研究细菌细胞如何调节这一代谢过程，以最大限度地提高其自身的资源利用效率。这些知识将使我们能够重新调整监管控制，以提高农业生产力。迄今为止，已经进行了一些简单的第一关尝试，以利用细菌氨输出用于植物生长，并且有些令人惊讶的是，这些一次关闭显示出希望，因为植物生长以表明来自细菌的减少的氮变得可用于支持植物生长的方式增强。我们的工作要求我们准确地量化用于确定细胞氮经济的各种关键小分子和蛋白质，并产生一种方案，从而我们可以干预并创造一种情况，即一些固氮酶衍生的氨从细菌细胞分泌到外部，而不会大大牺牲固氮细菌的生长和适应性。为了做到这一点，我们将使用捕捉控制系统的各种参与者不作为的方法，使我们能够找出主要的调节点发生在哪里，以及如何修改它们以获得氨输出功能而不失去有机体的适应性。这种方法要求我们将联合收割机实验与氮控制方案的建模相结合，并部署合成生物学工具来产生新的主基因调节蛋白，这将使我们能够捕获对细胞氮经济管理所需的整个复杂基因网络的控制。通过将这些方法与土壤细菌如何与植物根系建立密切联系并具有竞争力的知识和平行研究相结合，特别是它们如何从植物中获得碳作为能源，我们期望能够以可持续的方式改善植物的氮供应，以提高作物产量。此外，我们计划利用在该项目中获得的知识和理解，开发完全由太阳能驱动的含氮化学品工业生产的可再生生物技术工艺。

项目成果

Disrupting hierarchical control of nitrogen fixation enables carbon-dependent regulation of ammonia excretion in soil diazotrophs.

破坏对氮固定的分层控制，可以使土壤重生营养物中氨排泄的碳依赖性调节。

• DOI: 10.1371/journal.pgen.1009617
• 发表时间: 2021-06
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Bueno Batista M;Brett P;Appia-Ayme C;Wang YP;Dixon R
• 通讯作者: Dixon R

Transition state characteristics during cell differentiation.

• DOI: 10.1371/journal.pcbi.1006405
• 发表时间: 2018-09
• 期刊: PLoS computational biology
• 影响因子: 4.3
• 作者: Brackston RD;Lakatos E;Stumpf MPH
• 通讯作者: Stumpf MPH

Molecular origins of transcriptional heterogeneity in diazotrophic K. oxytoca

• DOI: 10.1101/2020.02.18.955476
• 发表时间: 2020-02
• 期刊: bioRxiv
• 作者: Tufail Bashir;Rowan D. Brackston;Christopher J. Waite;I. Kotta-Loizou;C. Engl;M. Buck;J. Schumacher

Disrupting hierarchical control of nitrogen fixation enables carbon-dependent regulation of ammonia excretion in soil diazotrophs

破坏固氮的层次控制使得土壤固氮生物中氨排泄的碳依赖性调节成为可能

• DOI: 10.1101/2021.03.25.436926
• 发表时间: 2021
• 作者: Batista M

Molecular Origins of Transcriptional Heterogeneity in Diazotrophic Klebsiella oxytoca.

• DOI: 10.1128/msystems.00596-22
• 发表时间: 2022-10-26
• 期刊: mSystems
• 影响因子: 6.4