초록
<P>Many researchers in the past decade have explored the controlled synthesis of calcium carbonate with specific size, morphology, and polymorphism. This study explored the biomimetic regulation of microbially induced calcium carbonate precipitation (MICP) via employing immobilization technology. Calcium alginate gel was used to immobilize <I>Sporosarcina pasteurii</I>, a urea-positive microorganism. CO<SUB>3</SUB><SUP>2–</SUP> was generated driven by ureolysis and reacted directly with Ca<SUP>2+</SUP> that was cross-linked in sodium alginate to produce CaCO<SUB>3</SUB> precipitation. Based on SEM, TEM, XRD, HRTEM, and SAED results, amorphous calcium carbonate, vaterite, and calcite appeared in order. This evolution of CaCO<SUB>3</SUB> morphology and polymorphism apparently conforms to Ostwald’s rule. Various concentrations (1–3%) of sodium alginate caused different alginate molecules to form due to the collapse of calcium alginate gel carrying negative charges and exerting a significant influence on the morphology of CaCO<SUB>3</SUB> from hexagonal vaterite to capsule-shaped vaterite. The techniques discussed here can also be applied to other polysaccharides on CaCO<SUB>3</SUB>, which implies that they are valuable with regard to polymorphic regulation because abundant polysaccharide apparently favors the vaterite polymorph.</P><P>This study explored the biomimetic regulation of microbially induced calcium carbonate precipitation via employing immobilization technology. Calcium alginate gel was used to immobilize urea-positive <I>Sporosarcina pasteurii</I>. CO<SUB>3</SUB><SUP>2−</SUP> was generated by ureolysis and reacted directly with Ca<SUP>2+</SUP>, and amorphous calcium carbonate, vaterite, and calcite appeared in order. The discussed techniques are applicable to other polysaccarides on CaCO<SUB>3</SUB>.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cgdefu/2017/cgdefu.2017.17.issue-4/acs.cgd.6b01813/production/images/medium/cg-2016-018134_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cg6b01813'>ACS Electronic Supporting Info</A></P>