ESTIMATION OF BIOACCUMULATIVE ABILITY OF HEAVY METALS BY BACILLUS BACTERIA WITH THE USE OF ROENTGEN-FLUORESCENT ANALYSIS AND ATOMIC FORCE MICROSCOPY
An ability of the Bacillus bacteria to accumulate heavy metals (Co, Pb, Cd, Zn) were studied by X-ray fluorescence analysis (XRF) and atomic force microscopy (AFM) methods. Minimal inhibitory concentrations of absorbed metals (Co, Pb, Cd, Zn, Mn, Fe) for each strain of microorganisms were established. Growth phases of Bacillus bacteria without metals and in the presence of their salts were defined. At cultivation with metals in certain cases there was an increase of time of bacteria outcome on a stationary growth phase. Dynamics of metals accumulation by microorganisms was studied by a method of the X-ray fluorescence analysis. Atomic force microscopy was used for study of bacteria morphology during heavy metals accumulation. The main morphometric parameters of cells in the presence of salts of metals and their absence were measured. It is shown that effect of salts of metals on microorganisms leads to reduction of cell sizes, deceleration of their growth and spores formation.