Iron-Oxidizing Bacteria in the Wetland Plant Rhizosphere: Characterization of a Novel Microbial Niche

湿地植物根际的铁氧化细菌：新型微生物生态位的表征

• 批准号: 9986981
• 负责人: James Megonigal
• 金额: $ 38.22万
• 依托单位: George Mason University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9986981&HistoricalAwards=false
• 关键词: Iron; Oxidizing; Bacteria; Wetland; Plant

Megonigal- DEB-9986981Iron-Oxidizing Bacteria in the Wetland Plant Rhizosphere: Characterization of a Novel Microbial NicheWetlands are places where iron changes form a reduced form (Fe2+) to an oxidized form (Fe3+) in the presence of O2. We know this process occurs around wetland plant roots because they often have a rust-colored Fe3+ coating. Most scientists believe Fe oxidation is spontaneous and that it does not involve microorganisms. However, we discovered bacteria on wetland plant roots that oxidize Fe3+ for energy and we suspect they control Fe oxidation rates in wetland soils. We also suspect that the Fe coatings that these organisms produce are more available to Fe-reducing microbes than those in the bulk soil. We will use laboratory and field experiments to test these hypotheses. The work is important because Fe cycling affects the behavior of several other elements including some pollutants. Of particular interest is the fact that iron cycling may affect the amount of methane released from wetlands; methane is a major greenhouse gas.

Megonigal-DEB-9986981湿地植物根际铁氧化细菌：一种新型微生物的特性湿地是指在氧气存在的情况下，铁从还原形式(Fe2+)转变为氧化形式(Fe3+)的地方。我们知道这一过程发生在湿地植物的根部周围，因为它们通常有铁锈色的Fe3+涂层。大多数科学家认为铁氧化是自发的，不涉及微生物。然而，我们在湿地植物根部发现了能够氧化Fe3+获得能量的细菌，我们怀疑它们控制着湿地土壤中的铁氧化速率。我们还怀疑，这些微生物产生的铁涂层比土壤中的铁涂层更容易被铁还原微生物利用。我们将使用实验室和现场实验来验证这些假设。这项工作很重要，因为铁的循环会影响其他几种元素的行为，包括一些污染物。特别令人感兴趣的是，铁循环可能会影响湿地释放的甲烷数量；甲烷是一种主要的温室气体。