Dissolution of red sandstones exposed to siderophore-producing bacterium Pseudomonas fluorescens: Experimental bioweathering coupled to a geochemical model

Abstract

Petrological and geochemical approach was implemented to decipher red sandstone dissolution under biotic conditions with bacteria, Pseudomonas fluorescens. Bacteria accelerated dissolution by up to 3.4 times as compared to abiotic weathering rates. The degree of sandstone dissolution was calculated at 0.2–0.6% and 0.2–3.7% for Kopulak and Tumlin sandstones, respectively. Further, goethite was found to be more susceptible to bacterially mediated Fe releases as compared to hematite. Cement structure was also found to affect leaching potential, while abiotic weathering revealed dissolution not exceeding 0.5%. Study proves that bioweathering processes may affect durability of sandstones used as construction and building materials and cultural heritage objects.