Organic insights into the bioprecipitation of carbonates in photosynthetic biofilms. A case study from La Laguna de Chiprana hypersaline lake (Spain).
Abstract
Within complex systems such as microbial mats formed in benthic environments, calcium carbonates are often associated with photosynthetic biofilms. This biocalcification regulates CO2, calcium and alkalinity in hydrosystems and is therefore highly sensitive to environmental and anthropogenic triggers. Deciphering biocalcification mechanisms is therefore a prerequisite for understanding present and past biogeochemical cycles. The photosynthetic activity of cyanobacteria could explain the presence of biocarbonates in biofilms (Ludwig et al., 2005), although the metabolic activity of sulfate-reducing bacteria can also be invoked (Dupraz and Visscher, 2005). Moreover, carbonates precipitation could be mediated by extracellular polymeric substances (EPS) or by macromolecules in dissolved organic matter (Gautret et al., 2006).
Origin : Files produced by the author(s)
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