Final Report: Molecular Basis for Microbial Adhesion and Geochemical Surface Reactions: A Study Across Scales

doi:10.2172/1084736

GSTDTAP > 地球科学

DOI	10.2172/1084736
报告编号	DOE-UA-15764
来源ID	OSTI ID: 1084736
	Final Report: Molecular Basis for Microbial Adhesion and Geochemical Surface Reactions: A Study Across Scales
	Dixon, David Adams [The University of Alabama]
	2013-06-27
出版年	2013
语种	英语
国家	美国
领域	地球科学
英文摘要	Computational chemistry was used to help provide a molecular level description of the interactions of Gram-negative microbial membranes with subsurface materials. The goal is to develop a better understanding of the molecular processes involved in microbial metal binding, microbial attachment to mineral surfaces, and, eventually, oxidation/reduction reactions (electron transfer) that can occur at these surfaces and are mediated by the bacterial exterior surface. The project focused on the interaction of the outer microbial membrane, which is dominated by an exterior lipopolysaccharide (LPS) portion, of Pseudomonas aeruginosa with the mineral goethite and with solvated ions in the environment. This was originally a collaborative project with T.P. Straatsma and B. Lowery of the Pacific Northwest National Laboratory. The University of Alabama effort used electronic structure calculations to predict the molecular behavior of ions in solution and the behavior of the sugars which form a critical part of the LPS. The interactions of the sugars with metal ions are expected to dominate much of the microscopic structure and transport phenomena in the LPS. This work, in combination with the molecular dynamics simulations of Straatsma and the experimental electrochemistry and microscopy measurements of Lowry, both at PNNL, is providing new insights into the detailed molecular behavior of these membranes in geochemical environments. The effort at The University of Alabama has three components: solvation energies and structures of ions in solution, prediction of the acidity of the critical groups in the sugars in the LPS, and binding of metal ions to the sugar anions. An important aspect of the structure of the LPS membrane as well as ion transport in the LPS is the ability of the sugar side groups such as the carboxylic acids and the phosphates to bind positively charged ions. We are studying the acidity of the acidic side groups in order to better understand the ability of these groups to bind metal ions. We need to understand the solvation properties of the metal ions in solution and their ability to bind not only to the sugars but to proteins and to other anions. Our goal is then to be able to predict the ability of the side groups to bind metal ions. One result from the earlier molecular dynamics simulations is the exclusion of water from the inner hydrophobic part of the membrane. We thus need to investigate the binding of the cations in media with different dielectric constants.
英文关键词	computational geochemistry
URL	查看原文
来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/6152
专题	地球科学
推荐引用方式 GB/T 7714	Dixon, David Adams [The University of Alabama]. Final Report: Molecular Basis for Microbial Adhesion and Geochemical Surface Reactions: A Study Across Scales,2013.