Exploring new growth modes and developmental trajectories for Streptomyces bacteria

链霉菌是一种土壤细菌，具有复杂的多细胞生命周期。经典的链霉菌的发育包括首先作为营养菌丝生长，然后提高气生菌丝并形成孢子链。值得注意的是，经典生长的殖民地扎根于原地，孢子传播是殖民新环境的唯一途径。我们最近发现了一种新的链霉菌行为，称为探索。探索文化在表面上迅速蔓延，扩张的速度是传统培养的10倍。我们发现，探索是在营养耗竭的情况下进行的，并受到其他生物的深刻影响。然而，我们最近的工作表明，可以通过多种方式进行探索。在发现了这一现象并开创了对这种新的细菌生长模式的研究之后，我们处于理想的地位，可以探索驱动探索的机制，以及影响探索的链霉菌和土壤中其他生物的相互作用。 目标1：确定管理探索的调控途径。我们已经确定至少有三条途径可以进行探索，并通过这三条途径中的每一条确定了专门控制探索的调控基因。我们的目标是绘制管理探索的调节级联，并确定驱动探索的基因和调节/代谢途径。 目的2：为快速生长和菌落扩张奠定机制基础。探索链霉菌是如何实现如此显著的菌落扩张的，这是完全未知的。我们有强有力的初步证据表明，这涉及到前所未有的细胞壁生物合成的重新编程。我们将在探测过程中探测细胞壁的结构和组成，跟踪探测过程中细胞壁生物合成关键酶的定位，并确定探测所需的细胞壁生物合成机械的性质。 目标3：探索探索的环境和生态影响。链霉菌是普遍存在的土壤微生物，探索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、昆虫和植物对探索的相互影响。我们将进一步研究在人造土壤和土壤微宇宙中的勘探，以确定环境中的勘探潜力。 这项研究计划的长期目标是了解影响细菌生长和发展策略的因素，以及这些因素如何影响这些有机体的生态。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。我们的发现进一步为以农业创新或生物修复为目的操纵链霉菌生长和相互作用的战略奠定了基础。

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.