Collaborative Research: Viral induced chemotaxis mediating cross-trophic microbial interactions and carbon flux

合作研究：病毒诱导的趋化性介导跨营养微生物相互作用和碳通量

• 批准号: 1829905
• 负责人: Sheri Floge
• 金额: $ 62.1万
• 依托单位: Wake Forest University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829905&HistoricalAwards=false
• 关键词: Collaborative; Research; Viral; induced; chemotaxis

Drifting photosynthetic microbes in surface ocean waters carry out nearly half of global carbon (C) fixation, both supporting the marine food web and reducing atmospheric carbon dioxide (CO2) levels. The fate of C in ocean ecosystems is controlled by myriad individual interactions within a highly interconnected planktonic food web, the sheer complexity of which has hindered predictive understanding of global C cycling. Chemical cues govern microbial interactions, and during infection, marine viruses manipulate the metabolism of phytoplankton and bacteria, facilitating the release of dissolved organic matter from infected cells. This research aims to determine how viral metabolic reprogramming of and organic matter release from intact, infected phytoplankton influences microbial interactions and C cycling. The interdisciplinary, collaborative nature of the project will enable direct training of two postdoctoral researchers, one graduate student, and undergraduate students in viral ecology, microfluidics, and metabolomics. An educational outreach program that engages middle school students in hands-on, high speed imaging of microbes will be expanded, and the project will culminate in a three-day workshop to advance the application of microfluidic devices and mass spectrometry analyses in microbial ecology.The overarching hypothesis behind this research is that viral infection alters the chemical landscape of intact, infected picophytoplankton cells, attracting neighboring chemotactic bacteria and protistan zooplankton, and altering C flux pathways. To test this idea, a series of linked multi-scale laboratory-based experiments will be run to 1) Characterize the response of diverse model marine microbes to dissolved organic matter (DOM) released from intact, virus-infected picophytoplankton using microfluidics-based chemotaxis assays, 2) Identify key viral-derived DOM compounds eliciting chemotactic responses using stable isotope labeling, metabolomics analyses, and chemotaxis assays, and 3) Quantify micron-scale cross-trophic encounter dynamics and evaluate their impact on bulk-scale C cycling using liter-scale measurements of C dynamics linked to high spatiotemporal resolution live imaging of microbial food webs. The ultimate goal of the project is to develop a mechanistic understanding of the role of intact, virus-infected cells in oceanic C cycling.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.

海洋表面沃茨中漂流的光合微生物进行了全球近一半的碳固定，既支持了海洋食物网，又降低了大气中的二氧化碳水平。C在海洋生态系统中的命运是由高度相互关联的浮游生物食物网中的无数个体相互作用控制的，其复杂性阻碍了对全球C循环的预测性理解。化学信号控制着微生物的相互作用，在感染过程中，海洋病毒操纵浮游植物和细菌的新陈代谢，促进溶解的有机物从感染细胞中释放出来。这项研究的目的是确定如何病毒的代谢重编程和有机物从完整的，受感染的浮游植物释放影响微生物的相互作用和碳循环。该项目的跨学科，协作性质将使两名博士后研究人员，一名研究生和本科生在病毒生态学，微流体学和代谢组学的直接培训。一个教育推广项目，让中学生动手，高速成像的微生物将扩大，该项目将在为期三天的研讨会上达到高潮，以促进微流控设备和质谱分析在微生物生态学中的应用。这项研究背后的首要假设是，病毒感染改变了完整的，受感染的微型浮游植物细胞的化学景观，吸引邻近的趋化细菌和原生浮游动物，改变碳通量途径。为了测试这一想法，将进行一系列基于实验室的多尺度实验，以1）使用基于微流体的趋化性测定来表征不同模式海洋微生物对从完整的、病毒感染的微微型浮游植物释放的溶解有机物（DOM）的响应，2）使用稳定同位素标记、代谢组学分析和趋化性测定来识别引起趋化性响应的关键病毒衍生的DOM化合物，和3）量化微米尺度的交叉营养遭遇动态和评估其对大规模的C循环的影响，使用升尺度的C动态测量与微生物食物网的高时空分辨率实时成像。该项目的最终目标是发展一个完整的，病毒感染的细胞在海洋碳循环中的作用的机械理解。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。