Microbial cycling of iron in acidic fens

酸性沼泽中铁的微生物循环

• 批准号: 5445019
• 负责人: Professorin Dr. Kirsten Küsel
• 金额: --
• 依托单位: Lehrstuhl Aquatische Geomikrobiologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5445019?language=en
• 关键词: Microbial; cycling; iron; acidic; fens

The manipulation experiments indicated that increased peat aeration at the fen Schlöppnerbrunnen did not eliminate the critical mechanism restricting the re-release of CO2 to the atmosphere as predicted by the enzymic latch hypothesis. However, manipulation renewaled the pool of alternative electron acceptors and shifted the electron flow from CH4 formation to alternative processes. Acetate was formed in soil microcosms, but the stimulation of CH4 formation or Fe(III) reduction was small. Surprisingly not the rate of Fe(II) formation was enhanced after rewetting but the time period was elongated, and maximum amount of Fe(II) formed increased in all soil depths suggesting a mobilization and subsequent oxidation of Fe(II) from deeper reduced soil horizons. Thus, the hypothesis of this project is that increased drying and rewetting events favor microbial Fe(III) reduction especially in peat layers below the surface due to iron minerals deposited by Fe(II) oxidizing bacteria. The main goals of project 2 are (1) to determine if drying and rewetting events affect the abundance of the active Fe(III)-reducing populations, (2) to estimate to which extent Fe(II)-oxidizing bacteria are involved in the deposition of iron minerals, and (3) to elucidate the microbial population involved in the oxidation of acetate.

的操作实验表明，泥炭通气增加分Schlöppnerbrunnen没有消除的关键机制限制重新释放的CO2到大气中的酶闩锁假说预测。然而，操作renewaled池的替代电子受体和电子流从CH4形成转移到替代过程。乙酸盐在土壤微宇宙中形成，但CH4形成或Fe（III）还原的刺激很小。令人惊讶的是，没有Fe（II）的形成率提高后，再润湿，但时间段被拉长，和最大量的Fe（II）形成增加，在所有的土壤深度表明动员和随后的氧化Fe（II）从更深的减少土壤的视野。因此，该项目的假设是，增加干燥和再润湿事件有利于微生物Fe（III）的减少，特别是在泥炭层以下的表面，由于铁（II）氧化细菌沉积的铁矿物。项目2的主要目标是（1）确定干燥和再润湿事件是否影响活性Fe（III）还原菌群的丰度，（2）估计Fe（II）氧化菌参与铁矿物沉积的程度，以及（3）阐明参与乙酸盐氧化的微生物种群。

项目成果

Impact of manipulated drought and heavy rainfall events on peat mineralization processes and source‐sink functions of an acidic fen

• DOI: 10.1029/2008jg000853
• 发表时间: 2009-06
• 期刊: Journal of Geophysical Research
• 作者: M. Reiche;A. Hädrich;G. Lischeid;K. Küsel