Characterizing and quantifying the impact of phagotrophic protists at hot spots of primary production at Axial Seamount

表征和量化吞噬原生生物对轴海山初级生产热点的影响

• 批准号: 1947776
• 负责人: Julie Huber
• 金额: $ 72.92万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947776&HistoricalAwards=false
• 关键词: Characterizing; quantifying; impact; phagotrophic; protists

Microorganisms are the ancestral forms of life on our planet and have been instrumental in shaping all of Earth’s environments into what they are today. In the ocean, microbial prokaryotes and eukaryotes form the foundation of marine food webs through their activity and interactions. Single-celled microbial eukaryotes (or protists) are some of the most important species on the planet, yet our understanding of how their activities influence and regulate the ocean ecosystem is poorly constrained. At deep-sea hydrothermal vents in particular, our understanding of microbial food web dynamics is incomplete without including the role of microbial eukaryotes. This project provides quantification of phagotrophic protistan grazing on the microbial communities inhabiting the highly productive diffuse vent mixing zone at hydrothermal vents, where the vent fluid-seawater interface promotes an increase in biological activity compared to the surrounding deep seawater. The results are contributing novel insights into the diversity and metabolic activities of the microbial eukaryotic community at vent fluid-seawater interfaces, establish the extent to which microbial eukaryotes impact primary production in the deep ocean by quantifying predation pressure, and estimate the amount of carbon transferred from primary producers to larger organisms. The investigators are training community college students from Cape Cod Community College by involving them in laboratory research through summer internships. The goal is to promote science, technology, engineering and math literacy among community college students through hands-on research experiences, peer-to-peer mentoring, and professional development opportunities, while also encouraging students to transfer to a four-year university, obtain a degree in a STEM subject, and continue on in a STEM field.Grazing by microbial eukaryotes is a significant source of mortality for microbes in the oceans, thus influencing the composition of communities and serving as a major route for remineralization of organic material to all organisms. This project is quantifying the in situ rates of eukaryotic grazing on prokaryotic communities at hot spots of primary productivity in the deep sea and characterize the diversity of microbial eukaryotes, their abundance, and metabolic activities at the seafloor. The focus of the effort is at the underwater volcano Axial Seamount, home of the Ocean Observatories Initiative (OOI) Regional Cabled Array with well-characterized low-temperature diffusely venting fluids. The two objectives of the work are to:1. Quantify the rates and impact of phagotrophic microbial eukaryote grazing on prokaryotic communities at the seafloor in low-temperature diffuse fluid mixing zones.2. Characterize microbial eukaryotic diversity, abundance, and metabolic gene expression at the seafloor in low-temperature diffuse fluid mixing zones.The modular Microbial Sampler-Submersible Incubation Device (MS-SID) is being used for in situ seafloor tracer incubations and compared to shipboard incubations for the proposed grazing studies. This combination of technology provides detailed and quantitative assessments of protistan communities and establishes the extent to which microbial eukaryotes impact primary production in the deep ocean. Expected outcomes include the quantification of protistan grazing rates on bacterial and archaeal communities within the seafloor mixing zone, comparison of predation pressure at the vent-seawater interface and surrounding deep ocean water, as well as identification of key bacteriovores, fungi, and other protists and associated major active metabolic pathways within the hydrothermal mixing zones. The project is providing a significant advance in the understanding of the microbial loop in the deep ocean as current depictions of microbial ecology at hydrothermal vent sites do not typically include the role of microbial eukaryotes.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.

微生物是地球上最古老的生命形式，在将地球所有环境塑造成今天的样子方面发挥了重要作用。在海洋中，微生物原核生物和真核生物通过它们的活动和相互作用形成了海洋食物网的基础。单细胞微生物真核生物（或原生生物）是地球上最重要的物种之一，但我们对它们的活动如何影响和调节海洋生态系统的理解却很少受到限制。特别是在深海热液喷口，如果不包括微生物真核生物的作用，我们对微生物食物网动态的了解是不完整的。该项目提供了摄食原生生物对栖息在热液喷口高产扩散喷口混合区的微生物群落的摄食量，与周围的深海相比，喷口流体-海水界面促进了生物活动的增加。这些结果有助于对喷口流体-海水界面微生物真核生物群落的多样性和代谢活动的新见解，建立微生物真核生物通过量化捕食压力影响深海初级生产的程度，并估计从初级生产者转移到较大生物体的碳量。调查人员正在培训科德角社区学院的社区大学生，通过暑期实习让他们参与实验室研究。其目标是通过实践研究经验、同行指导和专业发展机会，促进社区大学学生的科学、技术、工程和数学素养，同时鼓励学生转学到四年制大学，获得STEM学科的学位，并继续在STEM领域工作。微生物真核生物的放牧是海洋微生物死亡的重要来源，从而影响群落的组成，并作为有机物质向所有生物体转化的主要途径。该项目正在对深海初级生产力热点的原核生物群落的真核生物摄食率进行现场量化，并描述海底微生物真核生物的多样性、丰度和代谢活动。这项工作的重点是水下火山轴海山，海洋观测站倡议（OOI）区域电缆阵列的所在地，具有特征良好的低温扩散性喷口流体。工作的两个目标是：1。量化低温扩散流体混合区中食食性微生物真核生物对海底原核生物群落的摄食率和影响。描述低温扩散流体混合区海底微生物真核生物多样性、丰度和代谢基因表达的特征。正在使用模块化微生物取样器-潜水培养装置（MS-SID）进行海底原位示踪剂培养，并与拟议的放牧研究中的船上培养进行比较。这种技术的结合提供了对原生生物群落的详细和定量评估，并确定了微生物真核生物对深海初级生产的影响程度。预期成果包括量化原生生物对海底混合区内细菌和古菌群落的摄食率，比较喷口-海水界面和周围深海水的捕食压力，以及确定热液混合区内主要的食菌动物、真菌和其他原生生物以及相关的主要活跃代谢途径。该项目是对深海微生物循环的理解的一个重大进步，因为目前对热液喷口地点微生物生态学的研究通常不包括微生物真核生物的作用，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

Globally‐distributed microbial eukaryotes exhibit endemism at deep‐sea hydrothermal vents

全球分布的微生物真核生物在深海热液喷口表现出特有现象

• DOI: 10.1111/mec.16745
• 发表时间: 2022
• 期刊: Molecular Ecology
• 影响因子: 4.9
• 作者: Hu, Sarah K.;Smith, Amy R.;Anderson, Rika E.;Sylva, Sean P.;Setzer, Michaela;Steadmon, Maria;Frank, Kiana L.;Chan, Eric W.;Lim, Darlene S. S.;German, Christopher R.
• 通讯作者: German, Christopher R.

Integrating Multidisciplinary Observations in Vent Environments (IMOVE): Decadal Progress in Deep-Sea Observatories at Hydrothermal Vents

• DOI: 10.3389/fmars.2022.866422
• 发表时间: 2022-05
• 作者: M. Matabos;T. Barreyre;S. Juniper;M. Cannat;D. Kelley;Joan M. Alfaro-Lucas;V. Chavagnac;A. Colaço;J. Escartín;E. Escobar;D. Fornari;J. Hasenclever;J. Huber;A. Laës-Huon;N. Lantéri;L. Levin;S. Mihaly;E. Mittelstaedt;F. Pradillon;P. Sarradin;J. Sarrazin;B. Tomasi;R. Venkatesan;C. Vic

Protistan grazing impacts microbial communities and carbon cycling at deep-sea hydrothermal vents

原生生物放牧影响深海热液喷口的微生物群落和碳循环

• DOI: 10.1073/pnas.2102674118
• 发表时间: 2021
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Hu, Sarah K.;Herrera, Erica L.;Smith, Amy R.;Pachiadaki, Maria G.;Edgcomb, Virginia P.;Sylva, Sean P.;Chan, Eric W.;Seewald, Jeffrey S.;German, Christopher R.;Huber, Julie A.
• 通讯作者: Huber, Julie A.