Bacterial dormancy, bacterivory, and bacterioplankton diversity in the ocean

浮游细菌数量丰富，系统发育多样，具有多种生理功能。许多研究表明，大多数海洋浮游细菌是有生命的，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非活跃浮游细菌死亡的主要原因。一个长期存在的问题是，大多数休眠的浮游细菌如何在缺乏明显的物理庇护所的情况下存活下来，不受食草动物的伤害。PIS将研究浮游细菌休眠是否降低了被放牧的可能性，并以这种方式保持了遗传多样性的储存库，使社区层面能够对不断变化的环境条件做出快速反应。这将需要使用和进一步发展创新技术，将荧光激活的细胞分选与社区和单细胞分子分析相结合。这项尖端技术极大地提高了科学界解决以前因方法限制而无法解决的基本问题的能力。在浮游生物年度演替期间，将对缅因湾的一个沿海站和马尾藻海的一个寡养站进行研究，提供关于微生物营养相互作用的时间和空间变异性的信息。该项目将支持一名博士后助理和至少两名本科生。本科生将与毕格罗海洋科学教育和推广实验室团队合作，准备将他们的发现通过网络传播给非科学家。内容将在毕格罗实验室的网站上访问，链接自美国国家科学基金会资助的资源“食物网中的循环”(http://www.bigelow.org/bacteria/)，)，该网站为初中和高中观众促进对微生物食物网、生物多样性和全球营养循环的理解。PIS还将与海洋科学教育卓越中心-海洋系统(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.