Quantitative Studies of Bacterial Growth Physiology

细菌生长生理学的定量研究

基本信息

批准号：
10360530
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
项目类别：
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/10360530
关键词：
Acetates Acids Aerobic Affect Anaerobic Bacteria Animal Model Anions Bacteria Bacteroides Bacteroidetes Behavior Biochemical Butyrates Cells Colon Communities Complement Cytoplasm Data Engineered Probiotics Environment Enzymes Escherichia coli Eubacterium Exhibits Fermentation Firmicutes Fluorescence Foundations Genetic Goals Grant Growth Human 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 design environmental stressor fitness gut bacteria gut microbes gut microbiome gut microbiota improved member metabolomics microbiome research microbiota multiple omics mutant pathogen pathogenic bacteria predictive modeling programs ratiometric reconstitution response spatiotemporal

项目摘要

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.

项目概要该项目旨在阐明短链脂肪酸（SCFA）生长抑制作用的生理起源例如肠道微生物群中典型细菌种类的乙酸盐、丙酸盐和丁酸盐。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积累细胞质中的这些酸。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、比例荧光）与经典生化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识别的两个瓶颈联系起来这些方法将与正交扰动相结合，从而产生“过量的无用代谢物”。但不影响细胞内pH，另一个降低细胞内pH但不影响代谢物丰度，以量化每个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。上述研究将针对三种主要短链脂肪酸和四种示例性肠道细菌物种进行：特征模型生物大肠杆菌、鼠伤寒沙门氏菌和拟杆菌的致病菌株 thetaiotaomircon和Eubacteria直肠，来自拟杆菌门和厚壁菌门各自的丰富成员我们还将对表现出的关键突变体进行表征。对这些不同物种和突变体的结果进行比较将为我们提供一个结果。全面了解肠道细菌用于应对 SCFA 毒性的策略，以及这些策略的妥协在无应激条件下，策略会影响生物体的生长生理学。