Department of Biotechnology, Thapar University, Patiala, 147004, Punjab, India.
World J Microbiol Biotechnol. 2013 Dec;29(12):2397-406. doi: 10.1007/s11274-013-1408-z. Epub 2013 Jun 23.
Microbially induced calcium carbonate precipitation is a biomineralization process that has various applications in remediation and restoration of range of building materials. In the present study, calcifying bacteria, Bacillus megaterium SS3 isolated from calcareous soil was applied as biosealant to enhance the durability of low energy, green building materials (soil-cement blocks). This bacterial isolate produced high amounts of urease, carbonic anhydrase, extra polymeric substances and biofilm. The calcium carbonate polymorphs produced by B. megaterium SS3 were analyzed by scanning electron microscopy, confocal laser scanning microscopy, X-ray diffraction and Fourier transmission infra red spectroscopy. These results suggested that calcite is the most predominant carbonate formed by this bacteria followed by vaterite. Application of B. megaterium SS3 as biogenic surface treatment led to 40 % decrease in water absorption, 31 % decrease in porosity and 18 % increase in compressive strength of low energy building materials. From the present investigation, it is clear that surface treatment of building materials by B. megaterium SS3 is very effective and eco friendly way of biodeposition of coherent carbonates that enhances the durability of building materials.
微生物诱导碳酸钙沉淀是一种生物矿化过程，在修复和恢复各种建筑材料方面有广泛的应用。在本研究中，从钙质土壤中分离出的产脲酶、碳酸酐酶、胞外聚合物和生物膜的巨大芽孢杆菌 SS3 被用作生物密封剂，以提高低能耗、绿色建筑材料（土壤-水泥块）的耐久性。由 B. megaterium SS3 产生的碳酸钙多晶型物通过扫描电子显微镜、共焦激光扫描显微镜、X 射线衍射和傅里叶变换红外光谱进行了分析。这些结果表明，方解石是该细菌形成的最主要的碳酸盐，其次是文石。将 B. megaterium SS3 作为生物表面处理剂进行应用，可使低能耗建筑材料的吸水率降低 40%，孔隙率降低 31%，抗压强度提高 18%。从本研究可以清楚地看出，用 B. megaterium SS3 对建筑材料进行表面处理是一种非常有效和环保的方法，可以进行碳酸盐的生物沉积，从而提高建筑材料的耐久性。
