Biomineralization Function in Conservation of Calcareous Stone of Built Heritage: A perspective to the further investigations

Calcareous stones are one of the most widespread material in build heritage artifacts all around the world, and in particular, in Iran. Biomineralization is a common phenomenon in the nature which divided into authigenic and artificially induced mineralization. In two resent decades, bacteria-induced mineral precipitation based on the natural phenomenon, has been gradually extended to an innovative method to consolidate the stone of cultural heritage. Carbonatogenesis (biocalcification) is a term of bacterial mineralization of calcium carbonate that the carbonate productivity is strongly dependent on the mineralogy of the substrate. The aim of this study is introducing this new method and its advantage and limitation to the researchers in the field of microbiology who are interested in the cultural heritage materials. The Recent studies on biomineralization proved this method has too many advantages that the most important one is compatibility, and then, it has more advantages such as sealing the microcracks through biological carbonate, decreasing the porosity that results reduction of water absorption as well as providing an appropriate eco-friendly method. But, the depth of penetration of the cementing carbonate is often limited to less than a millimeter, also, some treatments create a sacrificial layer rather than substantial penetration. It is known, that the microbes can strongly contribute to stone deterioration, therefore, changes in the stone microbial community structure and growth of unwanted microorganisms could be a risk factor. In general, there are some factors that can influence on the results including particle size, solution ion content, grouting method, substrate concentration, temperature, pH, etc. In addition, there is a relationship between the quality of the calcium carbonate produced and the oxygen content in the environment, thus, microbial induced calcium carbonate precipitation from laboratory to field application is very different and needs more in situ investigations. In addition, the possibility of undesirable side-effects and risks to the stone that needs to be carefully evaluated.

کلیدواژه ها:

Biomineralization ، Calcareous Stone ، Built Heritage ، Carbonatogenesis ،