Étude de l'influence du rapport Mg/Ca sur la formation de carbonate par des bactéries telluriques

Abstract

An experiment was conducted to study the influence of the Mg/Ca ratio on CaCO₃ crystal formation by 96 isolates selected from 204 bacterial strains isolated from soil. Liquid and solid culture media were used with varying ratios of the ions, Mg and Ca; other media were used with similar Mg/Ca ratios, but in which the absolute quantities of the ions were varied. The crystals obtained were purified and identified by X-ray diffraction; in addition thermal differential analysis (ATD) and thermal gravimetric analysis (ATG) were utilized as complementary techniques. Calcite, aragonite, and struvite were identified, plus two different crystalline types, designated X and Y, which were not fully identified. The composition of the culture medium was found to have an influence on the speed and the type of crystals being precipitated. In solid culture media, it was more difficult to obtain aragonite precipitation.