Expression of alkaline phosphatase induces rapid and artificial mineralization in specific transformed Escherichia coli
Ohara, N.; Ohara, N.; Yanagiguchi, K.; Yamada, S.; Viloria, I.L.; Hayashi, Y.
New Microbiologica 25(1): 107-110
2002
ISSN/ISBN: 1121-7138 PMID: 11837385 Document Number: 540569
Matrix vesicles (MV) having high alkaline phosphatase (ALP) activity act as initiators of biological mineralization. Although bacteria have similar membranous structures to MV, ALP mediated mineralization has not been studied in bacterial cells. Escherichia coli was transformed with a bacterial ALP gene in this study. Recombinant E. coli overproducing ALP induced mineralization through hydrolysis of calcium-glycerophosphate (Ca-GP). Fourier transform infrared spectroscopy and electron microscopy combined with electron diffraction revealed newly formed hydroxyapatite mineral deposits. These findings suggest that hydrolysis of Ca-GP through ALP induced high Ca and Pi concentrations within bacterial cells followed by complete bacterial mineralization.