Nitrous oxide production by salt marsh sediment fungi: its significance and mechanisms

盐沼沉积物真菌产生一氧化二氮的意义和机制

• 批准号: 2303089
• 负责人: Xuefeng Peng
• 金额: $ 99.02万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2303089&HistoricalAwards=false
• 关键词: Nitrous; oxide; production; salt; marsh

Nitrous oxide is a potent greenhouse gas and ozone-depleting substance released from natural and agricultural environments. Coastal wetlands are one of the largest natural sources of nitrous oxide to the atmosphere, with most of the gas flux attributed to microbial processes in the sediment. In soil environments, fungi are significant contributors to nitrous oxide production, but in coastal wetlands the role of fungi is largely unknown. This project examines the role of understudied fungi in nitrous oxide production in salt marshes under varying environmental conditions in isolated fungal cultures and field-collected salt marsh sediments. Research findings are expected to improve future climate predictions and guide the restoration and management of salt marsh habitats to reduce nitrous oxide production. In addition to research training graduate and undergraduate students, this project will enhance scientific and conservation training to local high school students from diverse backgrounds through a partnership with a local zoo. This project aims to estimate the overall contribution of fungi to nitrous oxide release from salt marsh sediments and determine the metabolic basis for fungal nitrous oxide production under different oxidation-reduction and nutrient conditions. The researchers will cultivate fungi isolated from marsh sediments and use transcriptional profiling to reveal key genes that control nitrous oxide production. They hypothesize that salt marsh fungi produce nitrous oxide primarily by the anaerobic respiration of nitrate or nitrite. The project will constrain the contribution of fungi to nitrous oxide production with novel 15N-tracer incubations and inhibition of either the prokaryotic (i.e., bacteria) or the eukaryotic (i.e., fungi) components of the microbial community. This project will improve understanding of how microbial fungi survive the absence of oxygen and drastic daily changes in oxidation-reduction conditions.This project is jointly funded by Ecosystem Science and the Established Program to Stimulate Competitive Research (EPSCoR).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.

一氧化二氮是一种从自然和农业环境中释放的强效温室气体和臭氧消耗物质。沿海湿地是向大气排放一氧化二氮的最大天然来源之一，其中大部分气体通量归因于沉积物中的微生物过程。在土壤环境中，真菌是一氧化二氮产生的重要贡献者，但在沿海湿地中，真菌的作用在很大程度上是未知的。本项目研究了在不同的环境条件下，在隔离的真菌培养物和实地收集的盐沼沉积物中，未充分研究的真菌在盐沼一氧化二氮生产中的作用。研究结果有望改善未来的气候预测，并指导盐沼生境的恢复和管理，以减少一氧化二氮的产生。除了对研究生和本科生进行研究培训外，该项目还将通过与当地动物园的合作，加强对来自不同背景的当地高中生的科学和保护培训。本项目旨在评估真菌对盐沼沉积物氧化亚氮释放的总体贡献，并确定不同氧化还原和营养条件下真菌氧化亚氮产生的代谢基础。研究人员将培养从沼泽沉积物中分离出来的真菌，并利用转录谱来揭示控制一氧化二氮产生的关键基因。他们假设盐沼真菌主要通过硝酸盐或亚硝酸盐的厌氧呼吸产生一氧化二氮。该项目将限制真菌对一氧化二氮生产的贡献，使用新的15 N示踪剂孵育和抑制原核生物（即，细菌）或真核生物（即，真菌）微生物群落的组分。该项目将提高对微生物真菌如何在缺氧和氧化还原条件下生存的理解。该项目由生态系统科学和刺激竞争研究的既定计划（EPSCoR）共同资助。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。