Natural anaerobic degradation of methane and petroleum in marine sediments: geochemical gradients, degradation succession and microbial zonation

海洋沉积物中甲烷和石油的自然厌氧降解：地球化学梯度、降解演替和微生物分区

• 批准号: 210713498
• 负责人: Professor Dr.-Ing. Klaus Wallmann, since 10/2014
• 金额: --
• 依托单位: Forschungseinheit Marine Geosysteme
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/210713498?language=en
• 关键词: Natural; anaerobic; degradation; methane; petroleum

Petroleum is a complex mixture of hydrocarbons and other organic substances. Amongst the hydrocarbons, alkanes, cycloalkanes, and various aromatic compounds make up a large fraction. In the marine environment, petroleum naturally migrates through sediments from deeper reservoirs, passing different redox levels, electron acceptors and zones of microbial degradation processes. Thereby degradable carbon compounds enter the microbially active zone from the energetically lower end of the redox cascade, i.e., from the reduced zone, in opposite to oil spills that settle from the water column, i.e., from the oxygenated top. Consequently, the order of natural petroleum degradation in sediments starts with anaerobic processes through the utilization of different electron acceptors 'in reverse order' and ends with aerobic respiration. Given this flow direction, we expect the natural degradation succession of petroleum components to differ from conventional lab experimentations that concentrate on the degradation ability of selected organisms or enrichment cultures. The main objective of this project is to investigate the succession of microbial petroleum degradation in intact sediment cores from different marine locations simulating both situations: petroleum seepage from below and oil spill from top of the sediment. In addition, the performance of anaerobic oxidation of methane in the presence of petroleum will be explored. Geochemical and molecular methods will be applied to resolve the step-wise vertical degradation of petroleum and to identify the responsible microorganism.

石油是碳氢化合物和其他有机物的复杂混合物。在碳氢化合物中，烷烃、环烷烃和各种芳香族化合物占很大比例。在海洋环境中，石油通过深层储层的沉积物自然运移，经过不同的氧化还原水平、电子受体和微生物降解过程的区域。因此，可降解的碳化合物从氧化还原级联的能量较低的末端即从还原区进入微生物活性区，与从水柱即从氧化顶部沉降的溢油相反。因此，沉积物中天然石油降解的顺序从厌氧过程开始，通过不同电子受体的“反向”利用，以有氧呼吸结束。考虑到这个流动方向，我们预计石油成分的自然降解序列与传统的实验室实验不同，这些实验集中在选定生物或富集培养物的降解能力上。该项目的主要目的是研究来自不同海洋位置的完整沉积物岩心中微生物石油降解的演替过程，模拟两种情况：石油从下面渗出和从沉积物顶部溢出。此外，还将探讨甲烷在石油存在下的厌氧氧化性能。地球化学和分子方法将用于解决石油的逐级垂直降解和识别负责微生物。