Exploring new growth modes and developmental trajectories for Streptomyces bacteria

探索链霉菌新的生长模式和发育轨迹

• 批准号: RGPIN-2020-07197
• 负责人: Elliot, Marie
• 金额: $ 5.97万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745690
• 关键词: Exploring; new; growth; modes; developmental

Streptomyces are soil bacteria with a complex, multicellular life cycle. Classical Streptomyces development involves first growing as vegetative hyphae, then raising aerial hyphae and forming spore chains. Notably, classically-growing colonies are rooted in place, with spore dispersal being the only way of colonizing new environments. We recently discovered a new Streptomyces behaviour, termed `exploration'. Exploring cultures spread rapidly over surfaces, expanding at a rate >10 times faster than classically growing cultures. We found that exploration occurs in response to nutrient depletion and is profoundly impacted by other organisms. Our recent work is, however, suggesting that there are multiple ways by which exploration can occur. Having discovered this phenomenon and pioneered the investigations into this new bacterial growth mode, we are ideally positioned to probe the mechanisms driving exploration, and the interactions affecting both exploring Streptomyces and other organisms in the soil. OBJECTIVE 1: Define the regulatory pathways governing exploration. We have determined that there are at least three pathways by which exploration can proceed, and have identified regulatory genes specifically controlling exploration via each of the three pathways. We aim to map the regulatory cascades governing exploration and determine the genes and regulatory/metabolic pathways that drive exploration. OBJECTIVE 2: Establish the mechanistic basis for rapid growth and colony expansion. How exploring Streptomyces achieve such remarkable colony expansion is entirely unknown. We have strong preliminary evidence suggesting it involves an unprecedented reprogramming of cell wall biosynthesis. We will probe the structure and composition of the cell wall during exploration, follow the localization of key cell wall biosynthetic enzymes during exploration, and determine the nature of the cell wall biosynthetic machinery required for exploration. OBJECTIVE 3: Probe the environmental and ecological implications of exploration. Streptomyces are ubiquitous soil-dwelling microbes, and exploration has the potential to bring them in close contact with other organisms in the soil.  We will assess the reciprocal effects of bacteria, fungi, phage, insects and plants on exploration. We will further examine exploration in artificial soil and soil microcosms to determine the potential for exploration in the environment. The long term goal of this research program is to understand the factors that influence bacterial growth and developmental strategies, and how these impact the ecology of these organisms. This work will provide fundamental insights into the biology of Streptomyces, and has the capacity to develop new paradigms for bacterial growth and cell wall synthesis. Our findings are further laying the foundation for strategies aimed at manipulating Streptomyces growth and interactions for the purposes of agricultural innovation or bioremediation.

链霉菌是土壤细菌，具有复杂的多细胞生命周期。典型的链霉菌发育包括首先作为营养菌丝生长，然后产生气生菌丝并形成孢子链。值得注意的是，传统的殖民地是扎根在地方，孢子传播是殖民新环境的唯一方式。我们最近发现了一种新的链霉菌行为，称为“探索”。探索性培养物在表面上迅速传播，以比传统生长培养物快10倍的速度扩张。我们发现，探索发生在响应营养耗尽，并深刻地影响其他生物。然而，我们最近的工作表明，有多种方式可以进行探索。发现了这种现象并率先研究了这种新的细菌生长模式，我们处于理想的位置来探索驱动探索的机制，以及影响探索链霉菌和土壤中其他生物的相互作用。目标1：确定管理勘探的监管途径。我们已经确定，至少有三种途径，探索可以进行，并确定了调控基因，通过这三种途径中的每一个专门控制探索。我们的目标是绘制管理探索的调控级联，并确定驱动探索的基因和调控/代谢途径。 目标二：为链霉菌的快速生长和菌落扩展奠定了机理基础，但探索链霉菌如何实现如此显著的菌落扩展还完全未知。我们有强有力的初步证据表明，它涉及细胞壁生物合成的前所未有的重编程。我们将探索探索过程中细胞壁的结构和组成，探索过程中遵循关键细胞壁生物合成酶的定位，并确定探索所需的细胞壁生物合成机制的性质。目标3：探索勘探的环境和生态影响。链霉菌是无处不在的土壤微生物，勘探有可能使它们与土壤中的其他生物密切接触。我们将评估细菌，真菌，噬菌体，昆虫和植物对勘探的相互影响。我们将进一步研究在人造土壤和土壤微宇宙中的勘探，以确定在环境中勘探的潜力。 这项研究计划的长期目标是了解影响细菌生长和发育策略的因素，以及这些因素如何影响这些生物的生态。这项工作将为链霉菌的生物学提供基本的见解，并有能力为细菌生长和细胞壁合成开发新的范例。我们的研究结果进一步奠定了基础的战略，旨在操纵链霉菌的生长和相互作用的农业创新或生物修复的目的。