Bacterial dormancy, bacterivory, and bacterioplankton diversity in the ocean

浮游细菌数量丰富，系统发育多样，生理上多样。许多研究表明，大多数海洋浮游细菌是有活力的，但生理上不活跃或处于休眠状态。原生生物的放牧被认为是无活性浮游细菌死亡的主要原因。这是一个长期存在的问题，大多数休眠的浮游细菌是如何在没有明显的物理庇护所的情况下生存下来的。这些项目将研究浮游细菌的休眠是否会降低被放牧的可能性，并以此维持遗传多样性的储存库，从而使社区能够对不断变化的环境条件作出快速反应。这将需要使用和进一步开发创新技术，将荧光激活细胞分选与群落和单细胞分子分析相结合。这项尖端技术大大提高了科学界解决基础问题的能力，这些问题以前由于方法上的限制而无法实现。对缅因湾沿岸站和马尾藻海寡营养站进行年度浮游生物演替研究，提供微生物营养相互作用的时空变异信息。本项目资助博士后1人，本科生2人以上。这些本科生将与毕格罗海洋科学教育和推广实验室的团队合作，准备好他们的发现，以便在网上向非科学家传播。内容将在毕格罗实验室网站上提供，该网站链接自美国国家科学基金会资助的资源“通过食物网循环”（http://www.bigelow.org/bacteria/），旨在促进中学生对微生物食物网、生物多样性和全球营养循环的理解。这些学院还将与海洋科学卓越教育中心-海洋系统中心（COSEE-OS）密切合作，帮助学习者，特别是农村和内陆地区的学习者，更好地了解海洋在大地球系统中的作用。

Bacterioplankton are abundant, phylogenetically diverse, and physiologically versatile organisms. Many studies have demonstrated that the majority of marine bacterioplankton are viable but physiologically inactive or dormant. Grazing by protists is thought to be the main cause of mortality of inactive bacterioplankton. It is a long-standing question how a majority of dormant bacterioplankton can persist in the absence of apparent physical shelters from grazers. The PIs will examine whether bacterioplankton dormancy reduces the probability of being grazed, and in this way maintains a reservoir of genetic diversity, that enables rapid community-level responses to changing environmental conditions. This will require the use and further development of innovative technology, combining fluorescence-activated cell sorting with community and single-cell molecular analyses. This cutting-edge technology significantly enhances the scientific community's capability to address fundamental questions that were previously unattainable due to methodological constraints. A coastal station in the Gulf of Maine and an oligotrophic station in the Sargasso Sea will be studied during the annual plankton succession, providing information on the temporal and spatial variability in microbial trophic interactions. The project will support one postdoctoral associate and at least two undergraduate students. The undergraduate students will work with the Bigelow Laboratory for Ocean Sciences Education and Outreach team to ready their findings for web-based dissemination to non-scientists. Content will be accessible on the Bigelow Laboratory website, linked from the NSF-funded resource "Cycling through the Food Web" (http://www.bigelow.org/bacteria/), which promotes understanding of microbial food webs, biodiversity, and global nutrient cycling for middle and high school audiences. The PIs will also work closely with the Centers for Ocean Sciences Education Excellence-Ocean Systems (COSEE-OS) to aid learners, particularly those in rural and inland areas, to gain a better understanding of the role of the oceans in the greater earth system.