Biogeochemical Weathering of Layer Silicates

层状硅酸盐的生物地球化学风化

• 批准号: 9706382
• 负责人: Jillian Banfield
• 金额: $ 24.46万
• 依托单位: University of Wisconsin-Madison
• 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: 1997-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706382&HistoricalAwards=false
• 关键词: Biogeochemical; Weathering; Layer; Silicates

9706382 Banfield The proposed research will investigate the inorganic and biological mechanisms by which layer silicates are weathered, with implications for geochemical cycles, soil fertility, and plant nutrition. Specifically, work will focus on interactions between biotite, chlorite, muscovite, and rhizosphere microorganisms and the reactions that convert these minerals to clays. This work builds on our previous studies of inorganically and biogeochemically mediated alteration of chain silicates and extensive studies of layer silicate structures, microstructures, chemistry, and reaction mechanisms in hydrothermally altered rocks. Layer silicates partially transformed to clay minerals will be characterized using atomic-resolution transmission electron microscopy and state of the art energy-filtered electron microscopic techniques. Atomic-resolution and low dose image capture capabilities will be used to determine whether structural details of clay products are consistent with a transformation mechanism that involves structural inheritance. Our work will employ both weathered layer silicates from the rhizosphere region of natural soils and layer silicates weathered in a laboratory rhizosphere. The distribution of microorganisms on mineral surfaces will be studied using domain level and more specific oligonucleotide probes. The hypothesis that microorganisms in soils accelerate mineral dissolution by production of extracellular enzymes (e.g. "mineralases" , analogous to cellulases and chitinases microbes produce to degrade wood, chitin, and related organic substrates) will be tested. This work involves collaboration with Prof. Robert Goodman (Plant Pathology, UW-Madison.

9706382 Banfield提出的研究将研究硅酸盐层被风化的无机和生物学机制，对地球化学周期，土壤肥力和植物营养的影响。 具体而言，工作将集中于生物岩，氯酸盐，马云和根际微生物之间的相互作用以及将这些矿物转化为粘土的反应。 这项工作基于我们先前对链硅酸盐的无机和生物地球化学改变的改变以及对水热改变岩石中层硅酸盐结构，微结构，化学和反应机制的广泛研究的基础。 使用原子分辨率透射电子显微镜和TART ENergy-Terterterterlater的电子显微镜技术的状态，将部分转化为粘土矿物的层部分转化为粘土矿物。 原子分辨率和低剂量图像捕获能力将用于确定粘土产物的结构细节是否与涉及结构遗传的转换机制一致。 我们的工作将采用天然土壤根际的风化层硅酸盐，并在实验室根际中风化的硅酸盐层。 将使用域水平和更具体的寡核苷酸探针研究微生物在矿物表面上的分布。 通过产生细胞外酶（例如“矿物酶”（类似于纤维素酶和几丁质酶微生物产生以降解木材，奇异素和相关有机底物）产生的，土壤中的微生物通过产生细胞外酶加速矿物质溶解的假说。 这项工作涉及与罗伯特·古德曼（Robert Goodman）教授（UW-Madison的植物病理学）合作。