Collaborative Proposal: Anoxic Sediment Diagenesis at the Sulfate-Methane Interface: Does a Novel Microbial Syntrophy Result in Enhanced POC Remineralization?

合作提案：硫酸盐-甲烷界面的缺氧沉积物成岩作用：新型微生物合成是否会导致 POC 再矿化增强？

• 批准号: 0433322
• 负责人: William Berelson
• 金额: --
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2008-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0433322&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Anoxic; Sediment; Diagenesis

Organic carbon breakdown, or diagenesis, within continental margin sediments is an important component of the C cycle in marine sediments as its extent controls long-term burial rates. Scientists from University of Southern California, California Institute of Technology and University of Hawaii have hypothesized a novel diagenetic process that may result in enhanced carbon remineralization when both sulfate and methane are present. Based on preliminary data, this process appears to occur at a localized horizon (cm's thick) where there is a microbial syntrophic relationship between anaerobic oxidation of methane by archaea and sulfate reducing bacteria. They will study sediments of the Santa Barbara Basin using high-resolution pore water measurements to create models of the chemical gradients and calculate diffusive flux values. The microbial community will be described using total microbial cell counts, archaeal and bacterial 16S rDNA and dsrAB-based community characterization, and fluorescent in situ hybridization (FISH). Manipulative incubation experiments will attempt to induce higher rates of carbon remineralization by the addition of sulfate and or methane. The importance of this unique zone in anoxic marine sediments has potentially significant implications to current modeling approaches to carbon diagenesis, interpretation of paleoproxy records in marine sediments and to general understanding of sediment microbial community ecology. Collaboration between a microbiologist and two geochemists will illustrate the synergies created by interdisciplinary research to a wide range of students including REU, middle and high school students, as well as the graduate and undergraduate students participating in this collaboration on cruises and in data analysis.

大陆边缘沉积物中的有机碳分解或成岩作用是海洋沉积物中碳循环的重要组成部分，因为其范围控制着长期埋藏率。来自南加州大学、加州理工学院和夏威夷大学的科学家们假设了一种新的成岩过程，当硫酸盐和甲烷都存在时，这种过程可能会导致碳再矿化增强。根据初步数据，这一过程似乎发生在局部土层(厘米厚)，在那里古细菌对甲烷的厌氧氧化与硫酸盐还原细菌之间存在微生物共养关系。他们将使用高分辨率的孔隙水测量来研究圣巴巴拉盆地的沉积物，以建立化学梯度的模型，并计算扩散通量值。微生物群落将使用微生物细胞总数、古生菌和细菌16S rDNA和基于dsrAB的群落特征以及荧光原位杂交(FISH)来描述。人工培养实验将尝试通过添加硫酸盐和/或甲烷来诱导更高的碳再矿化率。这一独特的带在缺氧海洋沉积物中的重要性对当前碳成岩作用的模拟方法、海洋沉积物中古替代记录的解释以及对沉积物微生物群落生态学的一般理解具有潜在的重要意义。一名微生物学家和两名地球化学家之间的合作将向包括REU、初中生和高中生在内的广泛学生以及参与这一合作的研究生和本科生展示跨学科研究在巡航和数据分析方面所产生的协同效应。