Collaborative Research: Role of small-sized protists in the microbial loop with emphasis on interactions between mixotrophic protists and picocyanobacteria

合作研究：小型原生生物在微生物循环中的作用，重点是混合营养原生生物和微微蓝藻之间的相互作用

基本信息

批准号：
1458070
负责人：
Solange Duhamel
金额：
$ 53.08万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-01 至 2019-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1458070&HistoricalAwards=false
关键词：
Collaborative Research Role small sized

项目摘要

Protists are mostly single-celled, eukaryotic microorganisms, including algae and protozoans. They are ubiquitous, diverse, and major contributors in oceanic food webs. Determining their taxonomic identity and the extent to which they contribute to carbon and nutrient cycles (whereby carbon and minerals are continuously changed chemically in the environment and reincorporated in living organisms) are among the major goals of this study. Moreover, the investigators will study how they respond to environmental change, one of the most important and challenging current problems in oceanography. Answering these questions is fundamental to understanding how living organisms in the ocean environment interact with one another and contribute to the health and productivity of the ocean. The main goal of the project is to investigate biotic interactions of small-sized protists with very tiny cyanobacteria also known as picocyanobacteria, which represent the most abundant photosynthetic organisms in the ocean. These studies will be done both in ocean environments and in laboratory experimental settings. Considering the limited knowledge on this topic, the work planned in this project promises important and exciting discoveries. Two early career female scientists will lead this project. In addition, one postdoctoral scholar, one graduate student, and at least three undergraduate summer interns will participate in the proposed research activities. The principal investigators will create a strong public outreach program that will engage middle school students in hands-on activities related to ocean sciences, and will produce a video in collaboration with the Education Department at the American Museum of Natural History. The video will summarize the major findings of the proposed research. It can be used in schools and in informal learning settings, including access by the public on the Internet through the Museum's Science Bulletins web page.Single-celled eukaryotic microorganisms or protists, though largely outnumbered by picocyanobacteria (Prochlorococcus and Synechococcus), contribute significantly to ocean carbon biomass and primary productivity, partially by virtue of their larger cell size. In addition, small planktonic protists can regulate picocyanobacteria abundance through grazing. The main goal of this project is to investigate biotic interactions of planktonic pico- and nano-sized eukaryotes with picocyanobacteria, both in the field and in laboratory settings. A set of field- and culture-based experiments will be conducted, using state-of-the-art methodologies, including fluorescence-activated cell sorting, isotope and fluorescent stain labeling, and next-generation molecular sequencing to address the research objectives. Operationally, this project is structured around two objectives: Objective 1 is to assess the contribution of small protists to carbon and nutrient cycling through measurement of primary production, bacterivory, mixotrophy and phosphorus uptake in major microbial groups, and evaluate the role of nutrient availability in controlling mixotrophy. Objective 2 will focus on assessing the distribution and diversity of small-sized protists that feed on picocyanobacteria and further evaluate the role of nutrient availability among the protists that are mixotrophic. To reach these objectives field-based experiments will be conducted in contrasted environments: the North Pacific subtropical gyre (phosphorus replete, dominated by Prochlorococcus at Sta. ALOHA) and the North West Mediterranean sea (phosphorus deplete, dominated by Synechococcus at Sta. DYFAMED). Complementary experiments using model protists and picocyanobacteria will be conducted using controlled cultures in the lab. The work will provide critical new information on the phylogenetic diversity and function of marine microbial eukaryotes, with emphasis on their ecological role as predators (phagotrophy, mixotrophy) on, and competitors with, the picoyanobacteria Prochlorococcus and Synechococcus.

生物大多是单细胞的真核微生物，包括藻类和原生动物。它们是海洋食品网中无处不在，多样的和主要的贡献者。这项研究的主要目标是确定其分类学的身份以及它们对碳和营养周期的贡献程度（通过这种碳和矿物质在环境中不断变化并在活生物体中重新融合）是这项研究的主要目标。此外，调查人员将研究他们如何应对环境变化，这是海洋学目前最重要，最具挑战性的问题之一。回答这些问题是了解海洋环境中的生物如何相互作用并促进海洋的健康和生产力的基础。该项目的主要目的是研究小型生物与非常小的蓝细菌的生物相互作用，也称为皮基氨基细菌，这代表了海洋中最丰富的光合生物。这些研究将在海洋环境和实验室实验环境中进行。考虑到有关此主题的有限知识，该项目计划的工作有望有重要而令人兴奋的发现。两名早期职业女科学家将领导该项目。此外，一名博士后学者，一名研究生和至少三名本科暑期实习生将参加拟议的研究活动。首席调查人员将创建一个强大的公共宣传计划，该计划将与中学生一起进行与海洋科学有关的动手活动，并将与美国自然历史博物馆的教育部门合作制作视频。该视频将总结拟议研究的主要发现。它可以在学校和非正式的学习环境中使用，包括通过博物馆的科学公告网页上的公众在互联网上访问。细胞细胞的真核微生物或原生物学家，尽管在很大程度上被皮基甲虫类细菌超过了氯环杆菌（Prochorococcus and Synechococcus）的较大型号，供应较大的小组较大的较小的较小的较小的较小的较小的较小的较小的生产力。此外，小浮游生物可以通过放牧来调节皮基氨基细菌的丰度。该项目的主要目的是在野外和实验室环境中研究浮游生物和纳米尺寸的真核生物与皮基氨基细菌的生物相互作用。将使用最先进的方法（包括荧光激活的细胞排序，同位素和荧光染色标记）以及下一代分子测序来解决研究目标。在操作上，该项目是围绕两个目标结构的：目标1是通过测量主要微生物组的一级生产，细菌，混合动物和磷的摄取来评估小生物对碳和养分循环的贡献，并评估养分在控制混合物中的作用。目标2将着重于评估以果科底细菌为食的小型生物的分布和多样性，并进一步评估综合性营养性生物中营养物的可用性的作用。为了达到这些目标，将在对比的环境中进行基于现场的实验：北太平洋亚热带回旋（磷酸磷，由sta。Aloha的prochorococcus主导）和西北地中海海洋（Phosphorus Deplete）（磷deplete（由Synechococcus主导，在Sta。Sta。染色）。使用模型生物学家和皮基氨基杆菌的互补实验将使用实验室中的受控培养物进行。这项工作将提供有关海洋微生物真核生物的系统发育多样性和功能的关键新信息，重点是它们作为捕食者的生态作用（吞噬作用，混合植物），以及与picoyanobacteriabacteriabacteria prochorococcus and Synechococcus一起进行的竞争者。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Inorganic and organic carbon and nitrogen uptake strategies of picoplankton groups in the northwestern Atlantic Ocean

DOI：
10.1002/lno.11909
发表时间：
2021-08-13
期刊：
LIMNOLOGY AND OCEANOGRAPHY
影响因子：
4.5
作者：
Berthelot, Hugo;Duhamel, Solange;Cassar, Nicolas
通讯作者：
Cassar, Nicolas

Quantifying Per-Cell Chlorophyll a in Natural Picophytoplankton Populations Using Fluorescence-Activated Cell Sorting

使用荧光激活细胞分选定量天然超微型浮游植物种群中的每细胞叶绿素 a

DOI：
10.3389/fmars.2022.850646
发表时间：
2022
期刊：
Frontiers in Marine Science
影响因子：
3.7
作者：
Bock, Nicholas;Subramaniam, Ajit;Juhl, Andrew R.;Montoya, Joseph;Duhamel, Solange
通讯作者：
Duhamel, Solange

Microbial community structure in the western tropical South Pacific