Abstract
Magnetic contamination is considered more and more as a challenging issue related to biosphere pollution with magnetic
materials originating in natural and artificial sources (volcanic eruptions and respectively industrial activities that contributed to
iron and other metal compounds spreading in air, water and soil). Aiming to study the impact of magnetic metal ions such as iron
and cobalt on the metabolism of some environmental microorganisms, in this paper an experimental simulation of magnetic
contamination was carried out based on mixed iron/cobalt oxides as source of ions. Magnetic nanoparticles were prepared
following chemical route with appropriately adjusting of their surface to ensure uniform dispersion in water. Typical crystalline
structure of studied nanoparticles was evidenced with X-ray diffraction, while microstructural and magnetic properties were
investigated by scanning electron microscopy and respectively vibrating sample magnetometry. Increased level of peroxidase
activity in a fungus mycelium has suggested microorganism adaptation to higher levels of reactive oxygen species following the
supply with magnetic nanoparticles suspensions (0-10-20-30-35 mg/L, comparable with detected levels of iron in the living
organism). Lipid peroxidation was evidenced also; being assigned to the increased level of hydrogen peroxide that catalase seems
enable to balance - as resulted from its decreasing activity. The variations of analyzed indicators of oxidative stress were of no
more than 15%, reflecting organism adaptation to environmental constraints but also possible damages of cell membrane system.