The crystallization of calcium oxalate hydrates formed by interaction between microorganisms and minerals

Abstract

The work is devoted to the research of the interactions between microorganisms, rocks and minerals in simulation experiment conditions. Bacteria and microscopic fungi isolated from different types of rocks were studied as agents of biomineralization processes on the mineral surface in moist chamber and in liquid medium. The formation of calcium oxalates under the influence of fungi (Aspergillus and Penicillium) and bacteria (Bacillus) was observed on the surface of different calcium-bearing minerals: carbonates, phosphates, silicates. The obtained results allow to compare the role of microorganism metabolism, peculiarities of the stone substratum and the experimental conditions (the role of the environment) in calcium oxalate crystallization. It was shown that it is a complicated multifactor process. The metabolic activity of microorganisms affects the morphogenesis of the forming oxalates which can be explained by the difference in solubility of stone substrates in various metabolites. The results of simulation experiments showed that the metabolism of the microbial community is an important factor of secondary mineralization on the surface of rocks and minerals. The present results give a scientific basis for creating new methods for cultural heritage stone monument preservation with the use of modern biotechnologies.