Investigation of a microbially produced structural modification of magnesium-ammonium orthophosphate

Infrared spectroscopic, X-ray diffraction, thermogravimetric and microscopi c studies, atomic spectrometry, and ion chromatography trace elemental anal yses of insoluble mineral crystals produced in a synthetic phosphate-contai ning medium during cultivation of the soil bacterium Azospirillum brasilens e (strain Sp245) were carried out. The structure and chemical composition o f the mineral, including the entrapped metal cations, the distribution of t race impurities of biologically important cations between the cultivation m edium and the solid phase formed therein, and some aspects related to biomi neralization, are considered and discussed.