Ecological and Biological Aspects of Effect of Nanoparticles and Toxic Forms of Metals on Marine and Opportunistic Bacteria

We study the effects of new materials such as biogenic selenium and tellurium nanoparticles obtained earlier on the properties that determine the pathogenic potential of type bacterial cultures and aggressiveness of marine-derived strains. We compare the effect of nanoparticles on bacteria to that of known toxicants in several experiments to determine the growth characteristics and activity of enzymes on nutrient media and also their adhesion to human red blood cells. The following concentrations of toxicants were used: sodium selenite and potassium tellurite, 100 μg/mL; copper sulfate, 10 μg/mL; and selenium and tellurium nanoparticles, 100 μg/mL. We found that nanoparticles mainly inhibited the proteolytic, lipolytic, amylase, DNase, and hemolytic activities, whereas copper ions stimulated them. Selenium nanoparticles inhibited the pigment synthesis in Pseudomonas aeruginosa and Staphylococcus aureus. Nanoparticles and soluble forms of selenium and tellurium suppressed the bacterial adhesion to human red blood cells, while copper ions stimulated it. We also assessed the possible environmental risks of the emergence/use of the studied toxicants in the marine environment using an Artemia salina model. Based on the analysis of selenium and tellurium nanoparticles, we could classify them as nontoxic compounds, and sodium selenite, potassium tellurite, and copper sulfate, as toxic ones.