Abstract

This study deals with 16S-rDNA identified bacteria, Lysinibacillus sp., Raoultella sp., and Streptomyces sp. capable of precipitating CaCO₃ through nitrate reduction aerobically and anaerobically. The produced CaCO₃ crystals were analyzed using XRD, EDX, FTIR, TGA and SEM. The results showed that the carbonatogenic bacteria served as nucleation sites for CaCO₃ precipitation with distinct variation in polymorph and morphology; reflecting strain-specific property. Notably, the amount of precipitated CaCO₃ recorded 3.27 (aerobic), 1.55 (anaerobic), 4.15 (aerobic), 3.75 (aerobic) and 1.87 (anaerobic) g/100 mL of strains Lysinibacillus sp., Streptomyces sp. and Raoultella sp., respectively, after 240 h of incubation. The study of changes in media chemistry during carbonatogenesis process revealed positive correlation between bacterial growth, nitrate reductase activity, pH, EC, Ca²⁺ depletion, amount of deposited CaCO₃ and NO₃⁻ consumption. Therefore, the applications of these bacterial strains, which were employed for the first time in carbonatogenesis process, are promising in the environmental, biomedical and civil engineering fields.

摘要

本研究涉及经 16S-rDNA 鉴定的细菌Lysinibacillus sp。, Raoultella sp. 和链霉菌属。能够通过有氧和无氧还原硝酸盐来沉淀CaCO ₃。使用XRD、EDX、FTIR、TGA和SEM分析产生的CaCO ₃晶体。结果表明，碳酸化细菌作为CaCO ₃沉淀的成核位点，其多晶型和形态变化明显；反映应变特异性。值得注意的是，沉淀的 CaCO ₃的量记录为 3.27（需氧）、1.55（厌氧）、4.15（需氧）、3.75（需氧）和 1.87（厌氧）g/100 mL赖氨酸杆菌属菌种。,链霉菌属。和Raoultella sp。，分别在孵育 240 小时后。对碳酸生成过程中培养基化学变化的研究揭示了细菌生长、硝酸盐还原酶活性、pH、EC、Ca ²⁺消耗、沉积的CaCO ₃量和NO ₃ ^-消耗之间的正相关。因此，这些首次用于碳生成过程的菌株在环境、生物医学和土木工程领域的应用前景广阔。