title: Effect of Escherichia coliform on the biomineralization of calcium bilirubinate in mimic systems.
abstract: The influence of Escherichia coliform (E. coli), especially the proteins it secretes, on the nucleation, growth and aggregation processes of calcium bilirubinate (CaBR) in different mimic systems, such as NaCl aqueous solution and model bile, is studied in this paper. The results show that in NaCl aqueous solution the morphology of calcium bilirubinate (CaBR) changes from amorphous sheet structure to a highly self-organized and highly self-replicated fractal structure that is accumulated by rhombic microcrystals after the addition of E. coli. In model bile with the existence of E. coli, CaBR also forms a fractal structure, but the fractal structure is staghorn-like. Meanwhile, the composition of the prepared CaBRs is nonstoichiometric, and the crystallization is greatly improved with the existence of E. coli. Besides, formation mechanism of CaBRs affected by E. coli is explored, showing that the proteins secreted by E. coli interact with the Ca(2+) ions to provide nucleation sites for CaBRs, and the conformation of the proteins becomes more ordered, resulting in the improvement of the crystalline of CaBRs. On the other hand, the interaction of proteins and the Ca(2+) ions also promote the aggregation state of the CaBRs.
authors: School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039, PR China. s_ yuhua@163.com
authors: Yuhua
authors: Y
authors: Shen
authors: Qingfeng
authors: Q
authors: Zhang
authors: Long
authors: L
authors: Chen
authors: Anjian
authors: A
authors: Xie
authors: Xiangyun
authors: X
authors: Kong
authors: Liangbao
authors: L
authors: Yang
mesh_terms: D001663:Bilirubin / Q000378:metabolism*; D032701:Biomimetics; D002114:Calcinosis / Q000209:etiology* / Q000382:microbiology; D002769:Cholelithiasis / Q000209:etiology / Q000382:microbiology; D003460:Crystallization; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D001663:Bilirubin