The Nature of Bacterial Uncultivability

细菌不可培养的本质

• 批准号: 7259543
• 负责人: Kim Lewis
• 金额: $ 23.55万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-17 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7259543
• 关键词: Adenosylhomocysteine nucleosidase; Area; Bacteria; Cells; Coculture Techniques; Code; Diffusion; Discipline; Disruption; Drug Metabolic Detoxication; Drug resistance; Elements; Environment; Escherichia coli; Genes; Genetic; Goals; Growth; Growth Factor; Health; High Pressure Liquid Chromatography; Homologous Gene; Housekeeping; Human; In Vitro; Intestines; Isopropyl Thiogalactoside; Knock-out; Lead; Libraries; Metabolic; Methods; Microbiology; Modeling; Molecular; Nature; Numbers; Nutrient; Open Reading Frames; Oral; Organism; Parents; Pharmacologic Substance; Plasmids; Polymerase Chain Reaction; Production; Psychrobacter; Research; Science; Screening procedure; Shuttle Vectors; Signal Transduction; Signal Transduction Pathway; Simulate; Source; Testing; Variant; Work; base; expression cloning; expression vector; gallium alloy GF; gene cloning; microorganism; pathogen; prevent; promoter; receptor; response; tool; vector

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the molecular basis of bacterial unculturability. ~99% of all bacteria do not grow on synthetic media in vitro, which seriously undermines progress in microbiology, including critical areas related to human health. The established paradigm holds that unculturable organisms are either extremely slow growers, or require some unknown nutrients. In this proposal, we will test an alternative signaling hypothesis of unculturability - most microorganisms evolved to grow in a familiar environment, and will only propagate in response to signals from their surroundings. We have previously developed a method to grow unculturable bacteria by culturing them in a diffusion chamber placed in their natural environment (Kaeberlein, T., Lewis, K., and Epstein, S.S. 2002. Isolating "uncultivable" microorganisms in pure culture using a simulated natural environment. Science 296:1127-1129). Our preliminary findings indicate that growth on synthetic media of isolates from the chamber can be achieved by selection for domesticated variants; or in co-culture with "helper" species. These preliminary observations are consistent with the signaling hypothesis and form the basis of the present proposal. The goal of this project is to discover the genes controlling culturability of a model microorganism MSC33 related to culturable Psychrobacter. We were able to isolate a "domesticated" variant of MSC33 that grows well on a variety of synthetic media. This model will enable us to identify the genetic differences between the parent unculturable and the culturable derivative organisms. This work will be facilitated by a shuttle vector we developed based on an endogenous plasmid from MSC33. Finding the first culturability genes is the essential step toward elucidating the signal transduction pathway controlling growth which we will undertake in a subsequent RO1 project. The reasons preventing the majority of microorganisms from growing in the lab are unknown, and microbiology as a discipline has been restricted to the study of 1% of bacterial species. This project will advance our understanding of uncultivable bacteria, and will help develop tools to grow them. Unculturable bacteria are an enormous untapped source of potentially useful pharmaceutical compounds. Unculturable bacteria also make up most of the human oral and intestinal microflora. This project will advance our understanding of uncultivable bacteria, and will help develop tools to grow them. Unculturable bacteria are an enormous untapped source of potentially useful pharmaceutical compounds. Unculturable bacteria also make up most of the human oral and intestinal microflora.

描述（由申请人提供）：本项目的长期目标是了解细菌不可培养性的分子基础。约99%的细菌不能在体外合成培养基上生长，这严重破坏了微生物学的进步，包括与人类健康相关的关键领域。既定的范式认为，不可培养的生物要么生长极其缓慢，要么需要一些未知的营养。在这个提议中，我们将测试一个非可培养性的替代信号假说-大多数微生物进化为在熟悉的环境中生长，并且只会对来自周围环境的信号做出反应。我们先前已经开发了一种通过在置于其自然环境中的扩散室中培养不可培养的细菌来生长它们的方法（Kaeberlein，T.，刘易斯，K.，和Epstein，S. S. 2002.使用模拟的自然环境在纯培养物中分离“不可培养的”微生物。Science 296：1127-1129）。我们的初步研究结果表明，生长在合成培养基上的隔离室可以通过选择驯化的变种，或在共培养与“助手”的物种。这些初步观察结果与信号假说一致，并构成了本提案的基础。本项目的目的是发现与可培养的嗜冷杆菌相关的模式微生物MSC 33的可培养性控制基因。我们能够分离出MSC 33的“驯化”变体，其在各种合成培养基上生长良好。该模型将使我们能够识别亲本不可培养生物体和可培养衍生生物体之间的遗传差异。这项工作将促进穿梭载体，我们开发的基础上从MSC 33的内源性质粒。找到第一个可培养性基因是阐明控制生长的信号转导途径的重要一步，我们将在随后的RO 1项目中进行。阻止大多数微生物在实验室中生长的原因尚不清楚，微生物学作为一门学科仅限于研究1%的细菌物种。该项目将促进我们对不可培养细菌的理解，并将有助于开发培养它们的工具。不可培养的细菌是潜在有用的药物化合物的巨大未开发来源。不可培养的细菌也构成了人类口腔和肠道微生物群落的大部分。该项目将促进我们对不可培养细菌的理解，并将有助于开发培养它们的工具。不可培养的细菌是潜在有用的药物化合物的巨大未开发来源。不可培养的细菌也构成了人类口腔和肠道微生物群落的大部分。