REGULATION OF THE STRAIN Citrobacter freundii Ml-31.1/1 INTERACTION WITH IRON COMPOUNDS

The aim of the study was regulation of metabolism of Citrobacter freundii Ml-31.1/1 on the basis of thermodynamic calculations. The essence of metabolism regulation was in ability to perform two opposite processes, namely mobilization and immobilization of iron compounds, depending on the culture conditions by single strain C. freundii Ml-31.1/1. The following methods were used: potentiometric measuring of pH and Eh values, colorimetric determination of microbial biomass increase and changes of iron compounds concentration, gas chromatography. The possibility of theoretically grounded regulation of iron transformation pathways was experimentally confirmed. Single culture (C. freundii Ml-31.1/1) provided both immobilization and mobilization of iron compounds due to specific conditions for microbial growth in nutrient medium.. Obtained regularities are the basis for assessing the role of microorganisms in iron biogeochemical cycles. This data could be used as a basis of effective biotechnologies of iron extraction from depleted deposits and water purification from iron compounds.