Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine

Figure 4

Scanning electron micrographs (SEM and FESEM) of calcium carbonate crystals precipitated. (a), (b), (c), and (e) show bioliths produced in solid media in different stages of formation with morphologies of spheres and hemispheres and EDX spectrum; some bioliths show bacteria fingerprints on the surface. (d) and (g) are detail of the surface of some bioliths. (d) shows the surface of one calcified cell. (f) shows detail of (e), where the abundance of calcite nanoparticles delimiting the bacterial cell contours is evident. (g) and (h) show bioliths of monohydrocalcite precipitates in liquid medium and EDX spectrum. (h) shows detail of the biolith surface.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)