Quantitative Studies of Bacterial Growth Physiology

细菌生长生理学的定量研究

• 批准号: 10576807
• 负责人: TERENCE HWA
• 金额: $ 31.18万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10576807
• 关键词: Acetates; Acids; Aerobic; Affect; Anaerobic Bacteria; Anions; Bacteria; Bacteroides; Bacteroidetes; Behavior; Biochemical; Butyrates; Cells; Colon; Communities; Complement; Cytoplasm; Data; Endowment; Engineered Probiotics; Environment; Enzymes; Escherichia coli; Eubacterium; Exhibits; Fermentation; Firmicutes; Fluorescence; Foundations; Genetic; Goals; Grant; Growth; Human; Invaded; Knowledge; Laws; Link; Location; Measures; Metabolism; Methods; Modeling; Mus; Nutrient; Organism; Osmolar Concentration; Overdose; Pathogenicity; Physiological; Physiology; Play; Probiotics; Production; Progress Reports; Propionates; Protein Biosynthesis; Proteins; Proteome; Proteomics; Research; Research Personnel; Resistance; Role; Salmonella; Salmonella typhimurium; Shapes; Solid; Source; Spatial Distribution; Study models; Toxic effect; Transfer RNA Aminoacylation; Volatile Fatty Acids; Work; acid stress; bacterial community; cell growth; coping; design; environmental stressor; fitness; gut bacteria; gut microbes; gut microbiome; gut microbiota; improved; member; metabolomics; microbiome research; microbiota; model organism; multiple omics; mutant; pathogen; pathogenic bacteria; predictive modeling; programs; ratiometric; reconstitution; response; spatiotemporal

Project Summary This project aims to elucidate the physiological origin of the growth inhibitory effect of short-chain fatty acids (SCFA) such as acetate, propionate, and butyrate on exemplary bacterial species in the gut microbiota. Our preliminary data indicate that the affectors of SCFA toxicity are a reduction in intracellular pH and an accumulation of the anion form of these acids in the cytoplasm. A battery of high-throughput methods (quantitative metabolomics, quantitative proteomics, tRNA aminoacylation arrays, ratiometric fluorescence) are proposed together with classical biochemical approaches to identify the locations of the growth bottlenecks, and link their growth inhibitory effects quantitatively to the two identified affectors. These methods will be combined with orthogonal perturbations, one creating “overdose of useless metabolites” but not affecting intracellular pH, the other reducing intracellular pH but not affecting metabolite abundances, to quantify the effect of each perturbation on bacterial growth. The results obtained will be used to develop quantitative models that predict the % growth-reduction for a given SCFA level in the environment. The above studies will be done for each of the three major SCFAs and for four exemplary gut bacterial species: the best characterized model organism Echerichia coli, a pathogenic strain of Salmonella Typhimurium, and Bacteroides thetaiotaomircon and Eubacteria rectale, abundant members from the respective phyla of Bacteroidetes and Firmicutes which comprise the vast majority of the gut microbiota. We will additionally characterize key mutants that exhibit reduced SCFA-sensitivity. Comparisons of results for these different species and mutants will provide us with a comprehensive picture for strategies gut bacteria use to cope with SCFA toxicity, as well as the compromises these strategies impose on the growth physiology of the organisms in unstressed conditions.

项目摘要 本项目旨在阐明短链脂肪酸（SCFA）生长抑制作用的生理学起源 例如乙酸盐、丙酸盐和丁酸盐对肠道微生物群中的示例性细菌物种的影响。我们的初步数据 表明SCFA毒性的影响因素是细胞内pH值的降低和阴离子形式的 细胞质中的这些酸。一系列高通量方法（定量代谢组学，定量蛋白质组学， tRNA氨酰化阵列，比率荧光）与经典的生物化学方法一起提出， 确定生长瓶颈的位置，并将其生长抑制作用定量地与所确定的两个 影响者这些方法将与正交扰动相结合，其中一种方法会产生“过量的无用代谢物”。 但不影响细胞内pH，另一种降低细胞内pH但不影响代谢物丰度， 每种扰动对细菌生长的影响。所获得的结果将用于开发定量模型， 预测环境中给定SCFA水平的生长-减少百分比。 将对三种主要SCFA中的每一种和四种示例性肠道细菌物种进行上述研究： 表征的模式生物大肠埃希氏菌、鼠伤寒沙门氏菌的致病菌株和拟杆菌 thetaiotaomircon和直肠真杆菌，来自拟杆菌门和厚壁菌门各自门的丰富成员 它们构成了肠道微生物群的绝大多数。我们还将描述关键突变体， 降低SCFA敏感性。这些不同物种和突变体的结果比较将为我们提供一个 肠道细菌用于科普SCFA毒性的策略的全面图片，以及这些 策略在非应激条件下对生物体的生长生理施加影响。