Collaborative Research: Extracellular vesicles as vehicles for microbial interactions in marine Black Queen communities

海洋微生物群落的功能和稳定性取决于单个细胞之间生物产品和服务的交换。海洋微生物通常彼此相距很远，因此其中一些交换是通过将产品或服务释放到周围的水中而发生的，在周围的水中它们通过简单的扩散传播到其他细胞。了解一种生物体制造的此类有价值的产品在多大程度上针对特定合作伙伴以及如何针对我们对海洋微生物组的生态和进化的理解具有重要意义。该项目研究了一种人们知之甚少的非常小的颗粒——细胞外膜囊泡——在介导海洋内功能相互作用中所发挥的作用。细胞外囊泡由大多数海洋微生物释放，并且在海水中含量丰富，但我们对其功能的了解仍处于起步阶段。由于囊泡可以含有多种分子，包括活性酶，并在细胞之间运输它们，因此它们可以作为生态重要微生物之间交易的商品和服务的包装和传递系统。该项目更广泛的影响包括为本科生和研究生（包括来自 STEM 领域历史上代表性不足的群体的学生）提供实践研究经验，以及开发新的主动学习练习，以帮助增加对微生物在学生生活中所扮演的角色的了解。该项目探索多个尺度的囊泡功能，结合组学分析、现场实验和对多种生态重要微生物培养物的功能研究，以对囊泡对细胞交换的贡献有新的认识。这些实验结合了进化的视角，探索囊泡功能的范围和影响其产生的遗传机制，检查在数百代实验实验室进化之后，它们的内容物在浮游植物和异养细菌的共培养中如何变化。解决了基本的生态问题，涉及囊泡及其相关功能是否充当海洋中真正的“公共物品”，或者可以针对细胞子集，可能产生定义相互作用、合作网络的“俱乐部物品”。总的来说，这项工作将对海洋微生物相互作用的机制产生新的见解，并通过实验确定海洋微生物介导的贩运网络的功能潜力和生态影响。该项目由生物海洋学计划和刺激竞争性研究既定计划 (EPSCoR) 联合资助。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

The function and stability of microbial communities in the ocean depends on exchanges of biological products and services between individual cells. Marine microbes are typically far apart from one another, so some of these exchanges occur through the release of products or services into the surrounding water, where they travel to other cells via simple diffusion. Understanding the degree to which such valuable products made by one organism are targeted to a specific partner, and how, has important implications for our understanding of the ecology and evolution of the marine microbiome. This project examines the role played by a poorly understood type of very small particle – extracellular membrane vesicles – in mediating functional interactions within the oceans. Extracellular vesicles are released by most marine microbes and are abundant in ocean waters, but our understanding of their functions remains in its infancy. As vesicles can contain diverse molecules, including active enzymes, and transport them between cells, they may work as a packaging and delivery system for goods and services traded between ecologically important microorganisms. Broader impacts of the project include providing hands-on research experiences for undergraduate and graduate students - including those from groups historically underrepresented in STEM fields - and the development of new active learning exercises to help increase knowledge about the roles microbes play in students’ lives.This project explores vesicle functions across multiple scales, combining -omics analyses, field experiments, and functional studies in cultures of diverse and ecologically important microbes to arrive at new understandings of vesicle contributions to cellular exchanges. These experiments incorporate an evolutionary perspective for exploring the range of vesicle functions and genetic mechanisms affecting their production, examining how their contents have changed in co-cultures of phytoplankton and heterotrophic bacteria following hundreds of generations of experimental laboratory evolution. Fundamental ecological questions are addressed concerning whether vesicles, and their associated functions, act as truly ‘public goods’ in the oceans or can instead be targeted to a subset of cells, possibly yielding ‘club goods’ that define interacting, cooperative networks. Collectively, this effort will generate new insights into the mechanisms marine microbes use to interact with one another, and experimentally define the functional potential and ecological impact of EV-mediated trafficking networks in the oceans. This project is jointly funded by the Biological Oceanography Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.