Preparation of Calcite-Precipitating Bacteria-Embedded Magnesium Phosphate Cement for Self-Healing Application

Abstract

The present study was undertaken to check the feasibility of magnesium phosphate cement (MPC) for the immobilization of calcite-precipitating bacteria. An aqueous route of MPC synthesis was followed using magnesium phosphate Mg3(PO4)2 powder and ammonium phosphate solution. The Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy analysis confirmed the synthesis of MPC. Paenibacillus sp. NCIM 5410 was used due to its urea hydrolysis ability. The bacteria showed maximum urea hydrolysis at pH 9, 30 oC temperature, and after 72 h. The bacterial spores were incorporated during MPC synthesis which helped their immobilization. Around 70 (±0.48)% of urea was decomposed by the bacterial spore-containing MPC. Further, calcite precipitation was studied. The precipitate formed due to bacterial action in the MPC crack showed the presence of calcium. These results suggest that it is possible to synthesize bioactive MPC by encapsulating bacterial spores in MPC.