EAGER: Competition and interactions among predators of bacteria in microbial loop dynamics

美国国家科学基金会使用探索性研究早期概念补助金(EARGER)资助机制，支持未经检验但可能具有变革性的研究想法或方法的早期探索性工作。这个渴望的项目之所以被授予，是因为在亲爱的同事信NSF 16-080中，邀请来自历史悠久的黑人学院和大学的提倡者提交建议，以加强该机构教师的研究能力。佛罗里达农业与机械大学的这一项目旨在研究海洋水域中捕食性细菌--类蜈蚣弧菌(Balos)的生态作用。该项目的结果不仅可以揭示细菌捕食者之间的相互作用，也可以揭示在各种环境因素下捕食者和他们的猎物细菌之间的相互作用。这项研究的科学目标是：调查病毒、嗜盐杆菌和异养原生生物在细菌丰度下降过程中如何相互影响；量化所有三种死亡机制在细菌损失中的相对比例；确定环境对原生动物、病毒和嗜盐原生生物捕食活动的影响；以及模拟捕食者和猎物的种群动态。实现这些目标的方法是在实验室微观世界和野外研究中测量病毒、异养原生生物和盐生细菌对细菌死亡率的损失率。这种方法的新颖性和创新性在于，虽然这些组成部分中的许多都是独立检查的，但这将是这个复杂系统首次对死亡率进行定量划分。这一创新的早期探索性研究概念项目预期的高回报是变革性的结果，极大地提高了对三营养浮游相互作用的理解，这些相互作用显著影响了通过微生物环的海洋碳和营养物质的生物地球化学通量，并揭示了盐生细菌是一种主要的细菌捕食者。

The National Science Foundation uses the Early-concept Grants for Exploratory Research (EAGER) funding mechanism to support exploratory work in its early stages on untested, but potentially transformative, research ideas or approaches. This EAGER project was awarded as a result of the invitation in the Dear Colleague Letter NSF 16-080 to proposers from Historically Black Colleges and Universities to submit proposals that would strengthen research capacity of faculty at the institution. The project at Florida Agricultural and Mechanical University aims to study the ecological role of predatory bacteria, Bdellovibrio-like organisms (BALOs), in marine waters. The project outcome can reveal interactions not only amongst the bacterial predators but also among the predators and their prey bacteria under various environmental factors. The scientific objectives of this study are to: investigate how viruses, Halobacteriovorax, and heterotrophic protists effect one another in decreasing bacterial abundance; quantify the relative proportion of all three mortality mechanisms on bacterial loss; determine environmental effects on predatory activities of protists, viruses, and Halobacteriovorax; and model population dynamics of predators and prey. The approach to accomplishing these objectives is to measure loss rates of a virus, heterotrophic protist, and a Halobacteriovorax on the mortality of bacteria in laboratory microcosms and field studies. The novelty and innovativeness of this approach is that while many of these components have been examined independently, this would be the first time that mortality is quantitatively partitioned for this complex system. The expected high-payoff from this innovative Early-Concept for Exploratory Research project is transformative results that dramatically increase understanding of tri-trophic planktonic interactions that significantly influence oceanic biogeochemical fluxes of carbon and nutrients through the microbial loop and reveal Halobacteriovorax as a major bacterial predator.