Collaborative Research: Mixotrophic Grazing as a Strategy to meet Nutritional Requirements in the Iron and Manganese Deficient Southern Ocean

合作研究：混合营养放牧作为满足铁和锰缺乏的南大洋营养需求的策略

• 批准号: 2240781
• 负责人: Nicole Millette
• 金额: $ 17.59万
• 依托单位: College of William & Mary Virginia Institute of Marine Science
• 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: 2023-02-15 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2240781&HistoricalAwards=false
• 关键词: Collaborative; Research; Mixotrophic; Grazing; Strategy

Mixotrophs are essential components of the Antarctic planktonic community able to photosynthesize and also ingest small particles like bacteria to meet their nutritional needs. This project aims to understand the physiological response of mixotrophs exposed to micronutrient limitation in the Southern Ocean, specifically iron, manganese and simultaneous limitation of more than one trace metal, or colimitation. Such environmental conditions are characteristic of the Southern Ocean and can only be tested with local algae. The Principal Investigators hypothesize that under trace metal colimitation, some mixotrophs will have a competitive advantage by increasing their ability to consume particles to obtain energy and trace metals from their prey. Given the lack of understanding of how mixotrophs have adapted to the micronutrient limitation, the researchers propose studies with microalgal cultures isolated from the Southern Ocean; they will measure growth responses, consumption behavior, changes in cellular chemistry and transcription of genetic material in response to iron and manganese limitation. This project benefits the National Science Foundation goals of understanding Life in Antarctica and adaptation of organisms to this extreme environment. Society will benefit from the training proposed, whereby students from rural colleges will be instructed in computer coding and scientific data analyses. Furthermore, this work will support one graduate student, two undergraduate summer interns, and two early career scientists.The Principal Investigators hypothesize that under Fe-Mn colimitation, some mixotrophs will have a competitive advantage by increasing their grazing rates to obtain energy, Fe, and Mn from their prey. Given the lack of understanding of how mixotrophs have adapted to seasonal changes in the availability of these micronutrients and how they influence mixotrophic growth dynamics, the PIs propose culture studies to measure growth responses, grazing behavior, and changes in elemental stoichiometry in response to Fe and Mn limitation. Transcriptomic analyses will reveal the metabolic underpinnings of trophic behavior and micronutrient stress responses, with implications for key biogeochemical processes such as carbon fixation, remineralization, and nutrient cycling. Results are expected to clarify the ecological roles of Antarctic mixotrophs and elucidate the adaptations of Southern Ocean organisms to their unique polar ecosystem following the 2015 Strategic Vision for Polar Programs. This work will support one graduate student, two undergraduate summer interns, and two early career scientists. A series of virtual coding and bioinformatic workshops will be organized, in which basic principles of coding, and data processing used in the proposed analysis will be taught to undergraduate students. Small colleges in rural areas will be targeted for 8 modules on bioinformatics training.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.

混合营养生物是南极浮游生物群落的重要组成部分，能够进行光合作用，也能摄取细菌等小颗粒以满足其营养需求。该项目旨在了解南大洋混合营养生物对微量营养素限制的生理反应，特别是铁、锰和同时限制一种以上的微量金属或共营养。这种环境条件是南大洋的特征，只能用当地的藻类进行测试。主要研究人员假设，在痕量金属共模仿下，一些混合营养体将通过增加它们消耗颗粒的能力来获得竞争优势，从而从猎物中获得能量和痕量金属。由于缺乏对混合营养体如何适应微量营养素限制的了解，研究人员提出了从南大洋分离的微藻培养物的研究;他们将测量生长反应，消费行为，细胞化学变化和遗传物质转录对铁和锰限制的反应。该项目有利于国家科学基金会了解南极洲的生命和生物适应这种极端环境的目标。社会将从拟议的培训中受益，来自农村大学的学生将接受计算机编码和科学数据分析方面的指导。此外，这项工作将支持一个研究生，两个本科生暑期实习生，和两个早期的职业scientists.The首席研究员假设，根据铁锰colimitation，一些mixotrophs将有竞争优势，通过增加他们的放牧率，以获得能源，铁，锰从他们的猎物。由于缺乏了解如何mixotrophs已经适应了季节性变化，这些微量营养素的可用性，以及它们如何影响mixotrophs的生长动态，PI建议文化研究，以测量生长反应，放牧行为，并在元素化学计量的变化，以响应铁和锰的限制。转录组学分析将揭示营养行为和微量营养素应激反应的代谢基础，并对关键的生物地球化学过程（如碳固定、矿化和营养循环）产生影响。研究结果有望阐明南极混合营养生物的生态作用，并阐明南大洋生物在2015年极地计划战略愿景之后对其独特极地生态系统的适应。这项工作将支持一名研究生，两名本科暑期实习生和两名早期职业科学家。将组织一系列虚拟编码和生物信息学研讨会，向本科生讲授编码的基本原理和拟议分析中使用的数据处理。该奖项反映了NSF的法定使命，并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，被认为值得支持。