Laboratorio de Biorremediación, Facultad de Ciencias Biológicas, Universidad Autónoma de Coahuila, Carretera Torreón-Matamoros Km 7.5, Torreón, Mexico.
Facultad de Ingeniería, Ciencias y Arquitectura de la Universidad Juárez del Estado de Durango, Gómez Palacio, Mexico.
Environ Sci Pollut Res Int. 2018 Aug;25(22):21451-21458. doi: 10.1007/s11356-017-9347-0. Epub 2017 Jun 7.
In recent years, biomineralization process is being employed in development of bioconcrete, which is emerging as a sustainable method to enhance the durability of concrete by way of increasing compressive strength and reducing the chloride permeability. In this study, different bacterial strains isolated from the soils of the Laguna Region of Mexico were selected for further study. ACRN5 strain demonstrated higher urease activity than other strains, and the optimum substrate concentration, pH, and temperature were 120 mM, pH 8, and 25 °C, respectively. Further, Km and Vmax of urease activity of ACRN5 were 21.38 mM and 0.212 mM min, respectively. It was observed that addition of ACRN5 at 10 cells ml to cement-water mixture significantly increased (14.94%) in compressive strength after 36 days of curing and reduced chloride penetration. Deposition of calcite in bio-mortars was observed in scanning electron microscopy and energy dispersive X-ray diffraction spectrometry analyses. Results of this study demonstrated the role of microbially induced calcium carbonate precipitation in improving the physico-mechanical properties of bio-mortars.
近年来，生物矿化过程被应用于生物混凝土的开发中，这是一种通过提高抗压强度和降低氯离子渗透性来提高混凝土耐久性的可持续方法。在这项研究中，从墨西哥拉古纳地区的土壤中分离出不同的细菌菌株进行进一步研究。ACRN5 菌株的脲酶活性比其他菌株高，最佳底物浓度、pH 值和温度分别为 120 mM、pH 8 和 25°C。此外，ACRN5 菌株的脲酶活性的 Km 和 Vmax 值分别为 21.38 mM 和 0.212 mM min。观察到在水泥-水混合物中添加 10 个细胞 ml 的 ACRN5 菌株，在 36 天的养护后抗压强度显著提高（14.94%），氯离子渗透减少。在扫描电子显微镜和能量色散 X 射线衍射光谱分析中观察到生物砂浆中碳酸钙的沉积。这项研究的结果表明，微生物诱导碳酸钙沉淀在改善生物砂浆的物理力学性能方面发挥了作用。
