PNNL

Abstract

The adhesion of Pseudomonas aeruginosa to the goethite mineral is investigated using classical molecular simulation. A fragment model for goethite has been integrated into a fully atomistic membrane model. Properties for the resulting system are evaluated for a 1.5 ns simulation in the isothermal-isobaric ensemble. The response of the membrane to the presence of the mineral is investigated. Radial distribution functions are used to present an average picture of the hydrogen bonding. Orientational vectors, assigned to the saccharide groups, reveal the extent of the minerals perturbations on the membrane. Several of the outermost saccharide groups rotate to form hydrogen bonds with the mineral surface. Significant membrane structural changes were observed for saccharide groups directly adjacent to the mineral and the adjoining saccharide groups. The structure of the inner core, and the corresponding integrity of the membrane, is maintained. The mineral surface dehydrates slightly in the presence of the membrane as saccharide hydroxyl groups compete with water molecules for hydrogen bonding sites on its surface.