Calcite and dolomite dissolution rates in the context of microbe–mineral surface interactions

Abstract

Although microbes have been shown to alter the dissolution rate of carbonate minerals, a mechanistic understanding of the consequences of microbial surface colonization on carbonate dissolution has yet to be achieved. Here we report the use of vertical scanning interferometry (VSI) to study the effect of Shewanella oneidensis MR‐1 surface colonization on the dissolution rates of calcite (CaCO3) and dolomite (CaMg(CO3)2) through qualitative analysis of etch pit development and quantitative measurements of surface‐normal dissolution rates. By quantifying and comparing the significant processes occurring at the microbe–mineral interface, the dominant mechanism of mineral dissolution during surface colonization was determined. MR‐1 attachment under aerobic conditions was found to influence carbonate dissolution through two distinct mechanistic pathways: (1) inhibition of carbonate dissolution through interference with etch pit development and (2) excavation of carbonate material at the cell–mineral interface during irreversible attachment to the mineral surface. The relative importance of these two competing effects was found to vary with the solubility of the carbonate mineral studied. For the faster‐dissolving calcite substrates, inhibition of dissolution by attachment and subsequent extracellular polysaccharide (EPS) production was the dominant effect associated with MR‐1 surface colonization. This interference with etch pit development resulted in a 40–70% decrease in the surface normal dissolution rate relative to cell‐free controls, depending primarily on the concentration of cells in solution. However, in the case of the slower‐dissolving dolomite substrates, carbonate material displaced during the entrenchment of cells on the surface far outweighed the abiotic dissolution rate. Therefore, during the initial stages of surface colonization, dolomite dissolution rates were actually enhanced by MR‐1 attachment. This study demonstrates the dynamic and competitive relationship between microbial surface colonization and mineral dissolution that may be expected to occur in natural environments.

Microbial dissolution of calcite at T=28°C and ambient pCO2

“…Arguably however, most of this work has examined calcite dissolution from an inorganic perspective. Few experiments have quantified the effects of biological processes, and even fewer have explicitly isolated the role of microorganisms (Bennett et al, 2000;Friis et al, 2003;Lü ttge and Conrad, 2004;Davis et al, 2007). This contrasts with an extensive literature concerning microbial calcite precipitation (e.g., Kirkland et al, 1999;Tiano et al, 1999;Maliva et al, 2000;Bosak and Newman, 2003;Dittrich et al, 2004;Ferris et al, 2004;DeJong et al, 2006;Lian et al, 2006;Sanchez-Ro- man et al, 2007).…”

Caves in caves: evolution of post-depositional macroholes in stalagmites

“…For example, a strain of Shewanella oneidensis was allowed to colonize calcite and dolomite surfaces, resulting in a) inhibition of carbonate dissolution through interference with etch pit development; and b) excavation of carbonate material at the cell-mineral interface during bacterial attachment to the mineral surface (Davis et al, 2007). Other organisms known as active agents in biokarst are algae, fungi, lichens and other living macroforms (Vaughan et al, 2011, Fairchild andBaker, 2012).…”

Successive stages of calcitization and silicification of Cenomanian spicule-bearing turbidites based on microfacies analysis, Polish Outer Carpathians

“…Time-spa tial model of early diagenetic pro cesses which took place in neritic and slope en vi ron ments of the Silesian Ba sin bac te ria dur ing taphonomic-early diagenetic pro cesses, most prob a bly in soft, poorly ce mented car bon ate mud (B¹k M. et al, in press). Such cor ro sion of cal car e ous grains, caused by bac te ria, is known from var i ous mod ern and ancient en vi ron ments (e.g., Lüttge and Conrad, 2004;Da vis et al, 2007). The same ef fect of bac te rial cor ro sion is vis i ble on the cal ci fied spicules of sponges (Fig.…”