title: Biosynthesis of CaCO3 crystals of complex morphology using a fungus and an actinomycete.
abstract: The biosynthesis of CaCO3 by reaction of aqueous Ca2+ ions with a fungus, Fusarium sp., and an actinomycete, Rhodococcus sp. (both plant organisms), is described. In the case of the fungus, cruciform-shaped calcite crystals are obtained (SEM picture A) while the actinomycete yielded the unstable polymorph of CaCO3, vaterite (SEM picture B). Specific proteins secreted by the microorganisms are responsible for the morphology and crystallography control observed. A highlight of this approach is that the microorganisms also provide CO2 for reaction with the Ca2+ ions, making the crystals completely biogenic.
authors.affiliation: Materials Chemistry and Biochemical Sciences Division, National Chemical Laboratory, Pune-411 008, India.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Rautaray
authors.forename: Absar
authors.initials: A
authors.lastname: Ahmad
authors.forename: Murali
authors.initials: M
authors.lastname: Sastry
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry / Q000378:metabolism*; D005670:Fusarium / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D012240:Rhodococcus / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D002119:Calcium Carbonate