Sea-ice Snow Microbial Communities’ Impact on Antarctic Bromocarbon Budgets and Processes

海冰雪微生物群落对南极溴碳预算和过程的影响

• 批准号: 2031121
• 负责人: Karen Junge
• 金额: $ 42.26万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031121&HistoricalAwards=false
• 关键词: Sea; ice; Snow; Microbial; Communities

The ozone hole that develops over the Antarctic continent every spring is one of the features attributed to human activity, in particular production of the CFC (chlorofluorocarbons in refrigerants) released to the atmosphere. In spite of the CFC ban from the Montreal Protocol established in the year 1987, the recovery has been slower than predicted. Bromocarbons, known to produce the stratospheric ozone depletion, have recently been estimated to contribute to the pool of bromines in the lower atmosphere. What is the origin of the bromocarbons in Antarctic sea ice? Is this an additional source of chemicals creating the ozone hole? This project will test if bromocarbons in sea ice are produced and degraded by microalgae and bacteria found in sea ice, in snow and the interface between the two. The project will collect a suite of chemical and biological measurements of sea ice and snow to determine bromocarbon concentrations, microbial activity associated with them, and intra-cellular genes and proteins involved in bromocarbon metabolism. This project benefits NSF’s goals of expanding fundamental knowledge of Antarctic systems, biota, and processes, and improving the understanding of interactions among the Antarctic systems, cryosphere and organisms. The work will be carried out at McMurdo Station in late austral spring, including sampling of snow and ice that will be concentrated in the laboratory, and 24-hour experiments to measure algal and bacterial activity. Genes controlling synthesis of enzymes involved in bromocarbon metabolism are of interest in biotechnology and bioremediation, including products that repair damaged skin from UltraViolet Radiation. The project will train undergraduate students on chemical and biological techniques. The Principal Investigators will be involved in the Pacific Science Center in Seattle with ~10,000 visitors per weekend where they will develop a project-specific exhibit.The microbial processes in snow and ice associated with bromocarbon synthesis and degradation have not been studied in Antarctica during winter and spring. This study will inform about microbial activity in relation to the release of bromocarbons compounds from the snow and ice surfaces, compounds known to degrade stratospheric ozone. The estimation of chemical bromocarbons will be combined with metagenomics and metaproteomics approaches for understanding the potential role of microbes in snow and sea ice. The environmental, chemical and biological data will be synthesized with multivariate analysis and significant differences between sites and experimental treatments with ANOVA. A collaborator from the University of Goteborg in Sweden will collaborate on bromocarbon analyses. The study will also address “saline snow” a new environment not previously studied for microbial life. In addition, this is the first study of meta-proteomics in snow and ice. The Principal Investigators expect their results will help inform ozone hole recovery in the 21st century.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.

每年春天在南极大陆上空形成的臭氧空洞是人类活动造成的特征之一，特别是人类生产的氯氟烃（制冷剂中的氯氟烃）释放到大气中。尽管《蒙特利尔议定书》（Montreal Protocol）于1987年制定了氯氟烃禁令，但复苏速度比预期的要慢。已知会造成平流层臭氧耗竭的溴化碳最近被估计对低层大气中的溴池有贡献。南极海冰中溴化碳的来源是什么？这是造成臭氧层空洞的另一种化学物质来源吗？这个项目将测试海冰中的溴化碳是否由在海冰、雪和两者之间的界面中发现的微藻和细菌产生和降解。该项目将收集一套海冰和雪的化学和生物测量数据，以确定溴碳浓度、与之相关的微生物活动以及与溴碳代谢有关的细胞内基因和蛋白质。该项目有利于美国国家科学基金会扩大南极系统、生物群和过程的基础知识，并提高对南极系统、冰冻圈和生物之间相互作用的理解。这项工作将在南方春末在麦克默多站进行，包括在实验室集中采集冰雪样本，并进行24小时的实验来测量藻类和细菌的活动。控制溴碳代谢酶合成的基因是生物技术和生物修复领域的研究热点，包括修复紫外线辐射损伤皮肤的产品。该项目将对本科生进行化学和生物技术方面的培训。主要研究人员将在西雅图的太平洋科学中心参与，每个周末约有10,000名游客，他们将在那里开发一个特定项目的展览。尚未对南极冬季和春季冰雪中与溴碳合成和降解有关的微生物过程进行研究。这项研究将了解与从冰雪表面释放溴化碳化合物有关的微生物活动，这些化合物已知会降解平流层臭氧。化学溴化碳的估计将与宏基因组学和宏蛋白质组学方法相结合，以了解微生物在雪和海冰中的潜在作用。环境、化学和生物数据将通过多变量分析进行综合，并通过方差分析分析各试验点和试验处理之间的显著差异。来自瑞典哥德堡大学的一位合作者将合作进行溴碳分析。这项研究还将研究“盐水雪”，这是一种以前没有研究过的微生物生命的新环境。此外，这是首次在冰雪中研究元蛋白质组学。主要研究人员希望他们的结果将有助于了解21世纪臭氧空洞的恢复情况。该奖项反映了美国国家科学基金会的法定使命，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。