SIMONA DUNCA*, DORINA CREANGĂ**
*Faculty of Biology, “Alexandru Ioan Cuza” University, 11A, Carol I Blvd, 700506, Iaşi, Romania
**Faculty of Physics, “Alexandru Ioan Cuza” University, 11A, Carol I Blvd, 700506, Iaşi, Romania
Abstract. The effect of colloidal magnetite nanoparticles upon the growth of some bacteria identified recently as pathogens of the human body was studied aiming to reveal the possible side effects of ferrofluid aliquots residual after medical utilization. The stimulatory effect of small ferrofluid levels on the Serratia mercescens development was emphasized by means of turbidimetric assay and biomass measurements. For the highest ferrofluid concentration – 100 μL/L – the biomass accumulation at 30 hours was of about 1.5 higher than for the control sample while at 78 hours the biomass was almost double in comparison to the control. Turbidity level in the cell culture presents almost constant increase up to about 25% between 36 and 84 hours for ferrofluid concentrations of 80 and 100 μL/L.
Key words: Serratia marcescens, colloidal iron oxides, cell division, turbidimetric assay, mathematical correlation, microscope investigation.