Abstract
Although phosphate and carbonate are important constituents in ancient and modern environments, it is not yet clear their biogeochemical relationships and their mechanisms of formation. Microbially mediated carbonate formation has been widely studied whereas little is known about the formation of phosphate minerals. Here we report that a new bacterial strain, Tessarococcus lapidicaptus, isolated from the subsurface of Rio Tinto basin (Huelva, SW Spain), is capable of precipitating Fe-rich phosphate and carbonate minerals. We observed morphological differences between phosphate and carbonate, which may help us to recognize these minerals in terrestrial and extraterrestrial environments. Finally, considering the scarcity and the unequal distribution and preservation patterns of phosphate and carbonates, respectively, in the geological record and the biomineralization process that produces those minerals, we propose a hypothesis for the lack of Fe-phosphates in natural environments and ancient rocks.
Highlights
Authigenic ferrous iron-rich minerals like vivianite [Fe3(PO4)2 × 8H2O] and siderite (Fe2CO3) are used as indicators of paleoenvironmental conditions, diagenetic evolution of sedimentary sequences (Last and De Deckker, 1990; Manning et al, 1999; Sapota et al, 2006) and biosignatures (Vuillemin et al, 2013; Sánchez-Román et al, 2014)
transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of the bacterial precipitates show that Fe-phosphate crystals and Fe-carbonate spheroidal nanoparticles and in some cases, elongated nanoparticles were attached to the bacterial cells and EPS (Figures 2A–D, 3A,B,D, 4A,B)
Lapidicaptus Our TEM and SEM studies showed that carbonate and phosphate nanocrystals nucleated on bacterial cell surfaces and EPS (Figures 2, 3, 4)
Summary
Authigenic ferrous iron-rich minerals like vivianite [Fe3(PO4)2 × 8H2O] and siderite (Fe2CO3) are used as indicators of paleoenvironmental conditions, diagenetic evolution of sedimentary sequences (Last and De Deckker, 1990; Manning et al, 1999; Sapota et al, 2006) and biosignatures (Vuillemin et al, 2013; Sánchez-Román et al, 2014) They are usually found associated in organic rich environments like lacustrine (Lemos et al, 2007; Rothe et al, 2014) and deep-sea sediments (Dijkstra et al, 2014), swamps, sewage, and wastewater treatment plants (Postma, 1981; Lovley et al, 1991). Vivianite is found in decaying plants and animal tissues, bones, shells, anthropogenic compounds, human wastes, and archeological settings (Jakobsen, 1988; McGowan and Prangnell, 2006; Nutt and Swihart, 2012)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
