US GEOTRACES GP17-OCE and GP17-ANT: Cobalt Biogeochemical Cycling and Phytoplankton Protein Biomarkers in the Pacific and Southern Oceans

溶解金属作为影响海洋光合作用和整体碳循环的微量营养素具有重要作用。在这些金属中，钴是最稀缺的元素之一。钴在环境中具有不寻常的行为，因为它受到上层水体中的养分吸收过程以及中层水和深海中的清除过程的强烈影响。越来越多的证据表明钴在海洋生物过程中的重要性，其中不同化学形式的钴已被观察到影响初级生产力。此外，蛋白质生物分子与生物体内的大多数金属结合，对海洋微生物内蛋白质的研究可以提供有关微生物如何响应环境影响的有用信息。在本提案中，作为 GEOTRACES GP17-OCE 和 GP17-ANT 探险的一部分，研究人员将研究南太平洋和南大洋的钴和选定蛋白质的生物地球化学。 GEOTRACES 是一个研究微量元素和同位素分布的全球计划。该项目将支持一名研究生和一名博士后研究员。这两次探险将确定溶解和不稳定钴在南太平洋和南大洋的分布。此外，将跨表面横断面测量代表养分和微量养分胁迫的微生物蛋白质，以与金属的分布进行比较。南大洋和南极洲沿海地区对钴研究很感兴趣，因为据观察，由于季节性需求旺盛和冰川铁输入增加，含有钴原子的维生素 B12 会影响南极冰间湖浮游植物的生长。最近的数据表明，生物群使用维生素 B12 的增加可能会以多种方式改变钴生物地球化学循环，该项目将探索这些动态并将其与历史数据进行比较。在紫外线辐射去除金属结合配体后，将使用阴极溶出伏安法测量钴。蛋白质将通过使用纳喷雾液相色谱高分辨率质谱和宏转录组数据库的宏蛋白质组学方法进行测量。宏蛋白质组学结果将被纳入海洋蛋白质门户网站，以更广泛地用于研究和教育。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。

Dissolved metals have an important role as micronutrients that influence marine photosynthesis and the overall carbon cycle. Of these metals, cobalt is one of the scarcest elements. Cobalt has an unusual behavior in the environment in that it is strongly influenced by both nutrient uptake processes in the upper water column and scavenging removal processes in the mid-water and deep ocean. There is also growing evidence of cobalt's importance within marine biological processes where different chemical forms of cobalt have been observed to influence primary productivity. In addition, protein biomolecules bind most metals within organisms, and the study of proteins within marine microbes can provide useful information about how microbes respond to environmental influences. In this proposal, the investigator will study the biogeochemistry of cobalt and selected proteins across the South Pacific and Southern Oceans as part of the GEOTRACES GP17-OCE and GP17-ANT expeditions. GEOTRACES is a global program that studies the distribution of trace elements and isotopes. The project will support a graduate student and a postdoctoral researcher.The distributions of dissolved and labile cobalt will be determined across the South Pacific and the Southern Ocean on these two expeditions. Moreover, microbial proteins representative of nutrient and micronutrient stresses will be measured across surface transects to compare to the distributions of metals. The Southern Ocean and Antarctica coastal regions are of interest for cobalt research because vitamin B12, which contains a cobalt atom, has been observed to influence phytoplankton growth in Antarctic polynyas due strong seasonal demand and increased glacial iron inputs. Recent data suggests that this increased B12 use by the biota may be shifting the Co biogeochemical cycle in multiple ways, and this project will explore these dynamics and compare it with historical data. Cobalt will be measured using cathodic stripping voltammetry after ultraviolet radiation to remove metal-binding ligands. Proteins will be measured by metaproteomic methods that use nanospray liquid chromatography high resolution mass spectrometry and metatranscriptomic databases. Metaproteomic results will be incorporated into the Ocean Protein Portal for broader use in research and education.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.