We report a comparative investigation of the antibacterial activity of two water-soluble fullerene derivatives bearing protonated amine (AF) and deprotonated carboxylic (CF) groups appended to the fullerene cage via organic linkers. The negatively charged fullerene derivative CF showed no tendency to bind to the bacterial cells and, consequently, no significant antibacterial activity. In contrast, the compound AF loaded with cationic groups showed strong and partially irreversible binding to the negatively chargedEscherichia coliK12 TG1 cells and to human erythrocytes, also possessing negative zeta potential. Adsorption of AF on the bacterial surface was visualized by atomic force microscopy revealing the formation of specific clusters (AF aggregates) surrounding the bacterial cell. Incubation ofE. coliK12 TG1 with AF led to a dose-dependent bactericidal effect withLD50 = 79.1 µM. The presence of human erythrocytes in the test medium decreased the AF antibacterial activity. Thus we reveal that the water-soluble cationic fullerene derivative AF possesses promising antibacterial activity, which might be utilized in the development of novel types of chemical disinfectants.

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A comparative analysis of the four commercially available and laboratory luminescent sensor strains to the toxic effect of 10 carbon-based nanomaterials (CBNs) and 10 metal nanoparticles (MNPs) was carried out in this study. The bioluminescence inhibition assays with marine Photobacterium phosphoreum and recombinant Escherichia coli strains were varied in minimal toxic concentrations and EC 50 values but led to well-correlated biotoxicity evaluation for the most active compounds, which were ranked as Cu > (MgO, CuO) > (fullerenol, graphene oxide). The novel sensor strain Bacillus subtilis EG168-1 exhibited the highest sensitivity to CBNs and MNPs, which increased significantly the number of toxic compounds causing the bacterial bioluminescence inhibition effect.

The study was conducted to examine the effect of zinc nanoparticles on survival of worms Eisenia fetida and composition of the gut microflora. Analysis of the survival data has shown that the introduction of high doses of the nanoparticles causes death of worms in the second group with 35 % mortality rate and activates protective mechanisms realized as mucous film. DNA from the worm guts was extracted and 16S metagenomic sequencing was fulfilled using MiSeq (Illumina). Regarding the gut microflora of worms in the control group, high diversity of microorganisms (303 OTUs) was noted. Most of those belong to the taxa Firmicutes (51.9 % of the total high-quality united reads), Proteobacteria (24.1 % of the total), and Actinobacteria (13.3 % of the total), which were represented by numerous species of gen. Clostridium (C. saccharobutylicum, C. saccharoperbutylacetonicum, C. beijerinckii), gen. Pseudomonas (P. hydrogenovora, P. aeruginosa, and P. putida), gen. Bacillus (B. megaterium, B. silvestris), gen. Cellulomonas (B. megaterium, B. silvestris), and other numerically smaller genera. Adding of zinc nanoparticles to the substrate decreased the diversity of bacteria (78 OTUs) as well as percentage of bacteria belonging to the taxon Firmicutes (-41.6 %) and increased the proportion of Proteobacteria due to growth in abundance of gen. Verminephrobacter (+46 %) and gen. Ochrobactrum (+19.5 %).

The objective of the present study was to assess hair trace element content in Hereford heifers and cows (Bos taurus) living in South Ural region and calculate the site-specific reference intervals. Hair trace element content in 150 cows and heifers farmed in the Southern Urals of Russia was assessed using inductively coupled plasma mass-spectrometry. Dietary trace element content corresponded to the adequate values as estimated by recommendations of USSR State Agriculture Committee and U.S. National Research Council. Comparative analysis demonstrated that heifers are characterized by significantly higher hair Se (3-fold), Hg (4-fold), and Sn (46%) content, whereas cows had significantly higher levels of hair Co (56%), I (33%), Si (2-fold), V (27%), B (55%), Cd (19%), Pb (47%), and Sr (23%). At the same time, no significant group difference in hair Cr, Cu, Fe, Li, Mn, Zn, As, and Ni was detected between Hereford cows and heifers. The reference intervals and 90% confidence intervals for the lower and upper limits were calculated in agreement with the American Society for Veterinary Clinical Pathology Quality Assurance and Laboratory Standard Guidelines.