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个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。钴在环境中具有不同寻常的行为，它受到上层水柱的营养吸收过程和中水和深海的清除清除过程的强烈影响。也有越来越多的证据表明钴在海洋生物过程中的重要性，在海洋生物过程中观察到不同化学形态的钴影响初级生产力。此外，蛋白质生物分子结合了生物体内的大多数金属，对海洋微生物中蛋白质的研究可以提供关于微生物如何对环境影响做出反应的有用信息。在这项提案中，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上钴和选定蛋白质的生物地球化学。GeoTRACE是一个研究痕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人员。在这两次探险中，将确定南太平洋和南大洋上溶解和不稳定钴的分布。此外，代表营养和微量营养素压力的微生物蛋白质将跨表面横断面进行测量，以与金属的分布进行比较。南大洋和南极洲沿海地区对钴的研究很感兴趣，因为已观察到含有钴原子的维生素B12会影响南极多尼阿的浮游植物生长，因为季节性需求旺盛，冰川铁输入增加。最近的数据表明，生物群对B12的使用增加可能正在以多种方式改变钴的生物地球化学循环，该项目将探索这些动态，并将其与历史数据进行比较。钴将在紫外线照射后用阴极溶出伏安法测定，以去除金属结合配体。蛋白质将通过超蛋白质组学方法进行测量，这些方法使用纳米螺旋液色谱、高分辨率质谱学和后转录数据库。这个奖项反映了NSF的法定使命，通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为是值得支持的。

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.