Environmental and geochemical conditions of the formation of intracellular calcium carbonate

Cyanobacteria forming intracellular CaCO₃ have been found in a diversity of environments worldwide (Ragon et al., 2014; Benzerara et al., 2014). In particular, we have studied in more details the chemical conditions prevailing in Mexican lakes where we found G. lithophora and Synechococcus calcipolaris (Zeyen et al., 2017; Zeyen et al., in prep). Moreover, by culturing several strains forming intracellular CaCO₃ and analyzing the time changes in the chemical composition of the culture solutions, we showed that intracellular CaCO₃ biomineralization can occur in solutions undersaturated with CaCO3 and that these cyanobacteria tend to decrease the saturation level of their extracellular solutions on the contrary to many cyanobacteria (Cam et al. in press; De Wever et al., in prep).

Modern microbialites in Lake Alchichica (Mexico).