Biogeochemistry of Anaerobic Sedimentary Environments: An Integrated Geochemical and Microbiological Study of Dissimilatory Iron and Sulfate Reduction

厌氧沉积环境的生物地球化学：异化铁和硫酸盐还原的综合地球化学和微生物学研究

• 批准号: 9708535
• 负责人: Philippe Van Cappellen
• 金额: $ 25.5万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708535&HistoricalAwards=false
• 关键词: Biogeochemistry; Anaerobic; Sedimentary; Environments; Integrated

9708535 Van Cappellen A combined geochemical and microbiological approach is proposed to investigate the kinetic controls of dissimilatory iron (III) and sulfate reduction, two of the major respiratory pathways in anaerobic environments. Experiments will be performed using sediments collected in the saltmarsh of Sapelo Island, Georgia, where sulfate and iron reducing bacteria are major components of the microbial population. The co-investigators will use 16S rRNA-targeted oligonucleotide probes to detect sulfate- and Fe(III)-reducing bacteria, in conjunction with activity assays, phylogenetic screening, and kinetic flow-through reactor experiments. The molecular probes will establish the relative abundances of sulfate and iron reducing bacteria in the sediments core sections, and provide independent information to differentiate chemical and microbial pathways. The flow-through experiments on undisturbed sections of sediment cores will provide the kinetic data needed to derive rate expressions for the two dissimilatory pathways, as a function of temperature, substrate availability (organic matter, iron(III) oxyhydroxides, sulfate) and the composition of the pore solution (sulfide, nutrients, pH). The analysis of phylogenetically informative gene sequences will assess the similarity between the iron and sulfate reducing bacteria that propagate on the reactor systems and the naturally-occurring populations. This proposal was submitted in response to the Environmental Geochemistry and Biogeochemistry (EGB) solicitation, NSF 96-152. The proposed research is being jointly supported by the Divisions of Earth Sciences and Ocean Sciences.

提出了一种结合地球化学和微生物学的方法来研究厌氧环境中两个主要呼吸途径——异化铁（III）和硫酸盐还原的动力学控制。实验将使用在乔治亚州萨皮罗岛盐沼中收集的沉积物进行，硫酸盐和铁还原细菌是微生物种群的主要组成部分。联合研究人员将使用16S rrna靶向寡核苷酸探针检测硫酸盐和铁（III）还原细菌，并结合活性分析、系统发育筛选和动力学流动反应器实验。分子探针将建立沉积物岩心剖面中硫酸盐还原菌和铁还原菌的相对丰度，并为区分化学途径和微生物途径提供独立信息。在未受干扰的沉积物岩心剖面上进行的流动实验将提供所需的动力学数据，以得出两种异化途径的速率表达式，作为温度、基质可用性（有机物、铁（III）氢氧化物、硫酸盐）和孔溶液组成（硫化物、营养物质、pH值）的函数。系统发育信息基因序列的分析将评估在反应器系统上繁殖的铁和硫酸盐还原细菌与自然发生的种群之间的相似性。该提案是根据环境地球化学和生物地球化学（EGB）招标（NSF 96-152）提交的。拟议的研究是由地球科学司和海洋科学司共同支持的。