Cyanate in the Sea: Sources, Sinks, and Quantitative Significance

氮是世界海洋中的一种关键营养物质，因为除其他外，它是生物体的主要组成部分，可以成为初级生产力的驱动力。氮以多种有机和无机形式存在于海洋中，它们被海洋生物同化的程度各不相同。氰酸盐是海洋中存在的一种简单形式的有机氮，尽管人们对其丰度和对海洋氮循环的重要性知之甚少。使用新开发和测试的方法来测量环境中氰酸盐的浓度及其在海水中的吸收，研究人员将分析大西洋陆架水域中氰酸盐的分布、来源和地球化学。该项目的结果将阐明氰酸盐在海洋氮循环中的重要性，并改变对氰酸盐生产和海洋同化的理解。该项目将为研究生研究和本科生培训提供一个独特的机会，并可能使未被充分代表的群体接触海洋科学。尽管生理和基因组证据表明海洋微生物可以利用广泛的无机和有机氮化合物，但氰酸盐在海洋氮循环中的作用尚未得到检验。作为最简单的有机氮化合物之一，氰酸盐很可能在地球漫长的历史中一直存在于环境中。有证据表明，氰酸盐代谢很早就出现在细菌基因组中，因此，对当代海洋中氰酸盐同化的研究可能会揭示具有深刻进化根源的微生物过程。然而，在发现海洋蓝藻利用氰酸盐的基因组能力十年后，人们仍然对环境中氰酸盐的分布、氰酸盐的产生方式以及氰酸盐在海洋微生物中的广泛利用知之甚少。为了进一步了解氰酸盐在海洋氮循环中的作用，将使用多种地球化学方法来评估：1)氰酸盐在海洋环境中的分布，2)氰酸盐的潜在来源和产生氰酸盐的时间尺度，3)通过微生物吸收和自然分解去除氰酸盐的速率，以及4)氰酸盐生产和消费之间的地球化学耦合。这项研究产生的结果对于增进对海洋氮循环的知识、改进生物地球化学模型和进一步了解海洋微生物群落的功能将是重要的。

Nitrogen is a critical nutrient in the world's oceans because, among other things, it is a major component of living organisms and can be a driver in primary productivity. Nitrogen is present in the ocean in a number of organic and inorganic forms, which vary in their ease in being assimilated by marine organisms. Cyanate is a simple form of organic nitrogen present in the ocean, although its abundance and importance to the ocean nitrogen cycle is poorly understood. Using newly developed and tested methods for measuring ambient cyanate concentrations and its uptake in seawater, researchers will analyze the distribution, sources, and geochemistry of cyanate in shelf waters of the Atlantic Ocean. Results from this project will elucidate the importance of cyanate in the marine nitrogen cycle and transform understanding of cyanate production and assimilation in the sea. This project will provide a unique opportunity for both graduate student research and undergraduate training, and will likely expose underrepresented groups to marine sciences.Although physiological and genomic evidence suggest that marine microbes can utilize a broad array of inorganic and organic nitrogen compounds, cyanate's role in the marine nitrogen cycle has not yet been examined. As one of the simplest organic nitrogen compounds, cyanate has likely been present in the environment over Earth's long history. Evidence suggests that cyanate metabolism appeared early on in bacterial genomes and thus, the study of cyanate assimilation in the contemporary ocean may illuminate microbial processes with deep evolutionary roots. However, a decade since discovering the genomic capacity for cyanate utilization in marine cyanobacteria, little is still known about cyanate distributions in the environment, how it is produced, and how widespread cyanate utilization is among marine microbes. To further understanding of cyanate's role in the marine nitrogen cycle, a combination of geochemical approaches will be used to assess: 1) the distribution of cyanate in the marine environment, 2) potential sources of cyanate and the timescales at which cyanate is produced, 3) the rate of cyanate removal via microbial uptake and spontaneous decomposition, and 4) the geochemical coupling between cyanate production and consumption. Results generated from this study will be important for augmenting knowledge of the marine nitrogen cycle, refining biogeochemical models, and further understanding of the functioning of marine microbial communities.