Extending the new respiratory paradigm in Bacteroides

扩展拟杆菌的新呼吸范式

• 批准号: 10884591
• 负责人: Blanca Barquera
• 金额: $ 72.21万
• 依托单位: RENSSELAER POLYTECHNIC INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-18 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10884591
• 关键词: Address; Affect; Bacteria; Bacteroides; Bacteroides fragilis; Bile Acids; Biochemical; Biochemistry; Cell Respiration; Cell physiology; Code; Color; Communities; Complex; Consumption; Couples; Cytoplasm; Data; Dependence; Development; Developmental Process; Dietary Polysaccharide; Digestion; Drug Metabolic Detoxication; Ecosystem; Electron Transport; Electrons; Environment; Enzymatic Biochemistry; Enzymes; Fermentation; Food; Formulation; Funding; Generations; Genes; Genetic; Gnotobiotic; Growth; Health; Health Benefit; Human; In Vitro; Industrialization; Inflammation; Intestines; Ion Pumps; Knowledge; Metabolism; Molecular; Monosaccharides; Multienzyme Complexes; NADH; Nitric Oxide; Nitrites; Nutrient; Operon; Oxidants; Pathway interactions; Phenotype; Physiology; Polysaccharides; Population; Probiotics; Process; Production; Protons; Quinones; Regulation; Respiration; Respiratory Chain; Role; Source; Toxic effect; Translating; Variant; Vitamin K 2; Volatile Fatty Acids; Work; antiporter; bacterial fitness; design; dietary; electron donor; experience; experimental study; fitness; gut inflammation; gut microbiota; immunoregulation; improved; in vivo; isoprenoid; member; men; metabolomics; microbial; microbiota; mouse model; nitric oxide reductase; patient population; respiratory; respiratory enzyme; transcription factor; transcriptomics

Project Summary/Abstract Despite the tremendous amount of data that has been generated over the last 15 years regarding the human intestinal microbiota, we still know relatively little about energy generation processes of most of the abundant members of this ecosystem, including the Bacteroides. Our gap in this fundamental knowledge hinders our understanding of interactions between microbial members, how certain conditions in the gut environment affect microbial compositional changes, and how we may appropriately alter the composition of the ecosystem to improve human health. Bacteroides is one of the most abundant and stable bacterial genera of the human intestinal microbiota with strains colonizing their hosts for decades. During the first funding cycle of this project, we demonstrated that Bacteroides have a complex respiratory chain that provides substantial energy during both anaerobic and nanaerobic (0.1-0.15% O2) growth. Our studies revealed complexity at many steps in the respiration pathway and unexpected differences between Bacteroides species that will be pursued in this renewal application. These new aspects of respiration will be addressed in three specific aims. In Aim 1, we will study the important NUO complex that couples the transfer of electrons to menaquinone with creation of the proton gradient. The Bacteroides NUO complex is different than in most studied bacteria. In this aim, we will use genetics and biochemical analyses to conclusively identify the electron donor to NUO, determine the importance of NUO and Na+/H+ antiporters in maintaining the essential proton gradient, and determine the contribution of NUO and Na+/H+ antiporters to bacterial fitness in the mammalian gut. In Aim 2, we will study the acquisition and remodeling of the essential respiration component, menaquinone (MK). Most Bacteroides have all the genes necessary for the de novo synthesis of MK; however, certain Bacteroides species lack the primary men genes and must obtain and remodel dietary and/or microbial sources. We will explore unknown features of MK synthesis including how the isoprenoid chain is cleaved and remodeled, how Bacteroides species without the men operon obtain MK precursors, and the dietary and/or microbiota sources of these precursors. In Aim 3, we will study the NrfHA complex, the genes of which are among the most upregulated during nanaerobic growth. We predict NrfHA is an additional terminal electron donor that functions under nanaerobic conditions and donates electrons to both nitrite and nitric oxide (NO), detoxifying these molecules. We will study the regulation of the nrfHA operon revealing transcriptional factors that upregulate genes during nanaerobic growth, study its ability to donate electrons to both nitrite and NO, and determine if this complex allows Bacteroides to reduce host inflammation and better survive in the inflamed gut. The experiments of this proposal will reveal numerous aspects of basic physiology of the Bacteroides that can be translated for human health benefits.

项目摘要/摘要 尽管过去15年中已经产生了大量的数据 肠道菌群，我们仍然对大多数丰富的能源产生过程相对较少了解 该生态系统的成员，包括菌落。我们在这种基本知识中的差距阻碍了我们 了解微生物成员之间的相互作用，肠道环境中的某些条件如何影响 微生物组成的变化，以及我们如何适当地改变生态系统的组成 改善人类健康。细菌是人类最丰富，最稳定的细菌属之一 肠道菌群具有菌株，将其宿主定居数十年。在这个项目的第一个资金周期中， 我们证明了细菌具有复杂的呼吸链，可在 厌氧和鼻虫（0.1-0.15％O2）的生长。我们的研究揭示了许多步骤的复杂性 呼吸途径和细菌种类之间的意外差异将在 此更新应用。这些新的呼吸方面将以三个具体目标解决。目标 1，我们将研究重要的NUO复合体 创建质子梯度。细菌型NUO复合物与大多数研究的细菌不同。在 这个目的，我们将使用遗传学和生化分析来最终确定NUO的电子供体， 确定NUO和Na+/H+抗植物对维持必需质子梯度的重要性，并且 确定NUO和Na+/H+抗替代剂对哺乳动物肠道细菌适应性的贡献。目标 2，我们将研究基本呼吸成分甲酮酮（MK）的获取和重塑。 大多数细菌具有MK从头合成所需的所有基因。但是，可以肯定 细菌物种缺乏主要男性基因，必须获得和重塑饮食和/或微生物 来源。我们将探索MK合成的未知特征，包括如何裂解异丙链 并重塑，没有男性操纵子的杀菌物种如何获得MK前体，饮食 和/或这些前体的微生物源。在AIM 3中，我们将研究NRFHA复合体，即 这是鼻虫生长期间最上调的之一。我们预测NRFHA是一个额外的终端 电子供体在鼻虫条件下起作用，并将电子捐赠给亚硝酸盐和硝酸盐 氧化物（NO），排毒这些分子。我们将研究NRFHA操纵子的调节 转录因素上调鼻刺生长期间基因的转录因子，研究其捐赠电子的能力 对亚硝酸盐和否，并确定该复合物是否允许菌孢菌减少宿主炎症，并且 在发炎的肠道中更好地生存。该提案的实验将揭示基本的许多方面 可以转化为人类健康益处的菌孢子的生理学。