Collaborative Research: Investigating the relationship between size and the balance between carbon acquisition modes in mixotrophic protists

合作研究：研究混合营养原生生物体大小与碳获取模式平衡之间的关系

• 批准号: 2230103
• 负责人: Nicole Poulton
• 金额: $ 53.61万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2230103&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; relationship; between

Microplankton in aquatic systems have traditionally been categorized as phytoplankton or zooplankton. However, a growing body of research has documented that a substantial portion of plankton belongs to a third group, mixotrophs, that can use both photosynthesis and prey ingestion to obtain resources necessary to maintain growth. Biological oceanographers have a poor understanding of mixotrophs’ activity and their role in the aquatic food web due to the methodological challenges of studying them. In this project, the investigators are assessing how mixotrophs’ cell size relates to their dependence on photosynthesis and prey ingestion for nutrient acquisition. Among phytoplankton, size is considered a “master trait” because it impacts metabolic processes, growth rates, cellular composition, and nutrient uptake kinetics. While size has been used to constrain mixotrophic activity in some numerical models, the functional relationship between cell size and the balance of nutrient acquisition modes has not yet been empirically established. As part of broader impacts, all project investigators are participating in an Ocean Carbon and Biogeochemistry (OCB) mixotrophy working group. The project team includes early career investigators and is providing training to a postdoctoral scientist, graduate student, and multiple undergraduates through an established research experience for undergraduates (REU) program. Finally, educational outreach includes collaboration with a professional development program for science teachers, providing experiential science curricula and equipment kits for teaching ocean science in the classroom and outdoors. Mixotrophs obtain carbon from photosynthesis and ingestion simultaneously but the contribution from each nutrient mode to an individual organism is rarely measured simultaneously. Less is known about how the contribution of each nutrient mode differs between species and or with changes in growth-limiting factors. The investigators are conducting incubation experiments with eight species of mixotrophs to measure the proportion of carbon obtained from both nutrient acquisition modes across a range of environmental conditions. Using cutting-edge isotopic labelling methods, the investigators are assessing the relationship between cell size and trophic strategy among mixotrophs, with the potential for new, generalized understanding of carbon transfer and transformation in marine ecosystems. A relationship between mixotroph size and their two nutrient modes could transform biological oceanographers’ understanding of mixotrophs at the cellular and community levels, improve the accuracy of ocean ecosystem models, and enable more accurate predictions of how plankton communities and biogeochemical cycling will be altered with changing ocean conditions.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.

传统上，水生系统中的微浮游植物被归类为浮游植物或浮游动物。但是，越来越多的研究表明，浮游生物的很大一部分属于第三组Mixotrophs，可以同时使用光合作用和猎物摄入来获得维持生长所需的资源。生物海洋学家对综合营养的活性及其在水生食物网中的作用的了解不足，因为研究了它们的方法论挑战。在该项目中，研究人员正在评估混合营养的细胞大小如何与他们对光合作用和捕食营养获取的捕食有关。在浮游植物中，大小被认为是“主要特征”，因为它会影响代谢过程，生长速率，细胞组成和营养摄取动力学。尽管大小已用于在某些数值模型中限制综合性活性，但尚未紧急建立细胞大小与养分获取模式之间的功能关系。作为广播公司影响的一部分，所有项目研究人员都参加了海洋碳和生物地球化学（OCB）Mixotrophy工作组。该项目团队包括早期的职业调查人员，并通过既定的本科生（REU）计划的研究经验为博士后科学家，学生和多个本科生提供培训。最后，教育宣传包括与科学教师专业发展计划的合作，为在课堂和户外教授海洋科学的经验科学课程和设备套件提供。混合芽孢杆菌同时从光合作用和摄入中获得碳，但是很少能简单地测量每种营养模式对单个生物体的贡献。关于每种养分模式的贡献与物种之间的贡献以及生长限制因素的变化之间的贡献较少。研究人员正在与八种混合营养物种进行孵育实验，以测量从两种养分获取模式中在各种环境条件下获得的碳的比例。使用尖端的同位素标记方法，研究人员正在评估混合营养中细胞大小与营养策略之间的关系，并有可能对海洋生态系统中的碳转移和转化进行新的广泛理解。混合营养大小及其两种营养模式之间的关系可以改变生物学海洋学家对细胞和社区水平上的混合营养的理解，提高了海洋生态系统模型的准确性，并可以更准确地预测浮游生物群落和生物地球化学的循环如何通过改变海洋的奖励来改变nsf的基础。优点和更广泛的影响审查标准。