INHIBITION OF HYDROXYAPATITE CRYSTAL-GROWTH BY LIPOTEICHOIC ACID

Lipoteichoic acids were purified from freshly isolated strains of Stre ptococcus sanguis and Lactobacillus casei, and from a laboratory strai n of Strep. rattus BHT. Their effects on the seeded growth of hydroxya patite in 1 mM CaCl2, 7.5 mM KH2PO4, 50 mM HEPES (pH 7.2) were determi ned. At lipoteichoic acid concentrations of 25 muM organic phosphate ( P(o)) and higher, the growth of hydroxyapatite appeared to be inhibite d, at 100 muM P(o) inhibition was complete for several hours. In contr ast, low concentrations of lipoteichoic acids (5-10 muM P(o)) may have a stimulatory effect on the seeded growth of hydroxyapatite. It was c oncluded that lipoteichoic acid may be one of the bacterial products t hat inhibit enamel lesion repair in vivo.