Assessment of the toxicity of silicon nanooxide in relation to various components of the agroecosystem under the conditions of the model experiment.

Investigation of SiO2 nanoparticles (NPs) effect on Eisenia fetida showed no toxic effect of the metal at a concentration of 250, 500 and 1000 mg per kg of soil, but conversely, a biomass increase from 23.5 to 29.5% (at the protein level decrease from 60 to 80%). The reaction of the earthworm organism fermentative system was expressed in the decrease in the level of superoxide dismutase (SOD) on the 14th day and in the increase in its activity to 27% on the 28th day. The catalase level (CAT) showed low activity at average element concentrations and increase by 39.4% at a dose of 1000 mg/kg. Depression of malonic dialdehyde (MDA) was established at average concentrations of 11.2% and level increase up to 9.1% at a dose of 1000 mg/kg with the prolongation of the effect up to 87.5% after 28-day exposure. The change in the microbiocenosis of the earthworm intestine was manifested by a decrease in the number of ammonifiers (by 42.01-78.9%), as well as in the number of amylolytic microorganisms (by 31.7-65.8%). When the dose of SiO2 NPs increased from 100 to 1000 mg/kg, the number of Azotobacter increased (by 8.2-22.2%), while the number of cellulose-destroying microorganisms decreased to 71.4% at a maximum dose of 1000 mg/kg. The effect of SiO2 NPs on Triticum aestivum L. was noted in the form of a slight suppression of seed germination (no more than 25%), an increase in the length of roots and aerial organs which generally resulted in an increase in plant biomass. Assessing the soil microorganisms' complex during introduction of metal into the germination medium of Triticum aestivum L., there was noted a decrease in the ammonifiers number (by 4.7-67.6%) with a maximum value at a dose of 1000 mg/kg. The number of microorganisms using mineral nitrogen decreased by 29.5-69.5% with a simultaneous increase in the number at a dose of 50 mg/kg (+ 20%). Depending on NP dose, there was an inhibition of the microscopic fungi development by 18.1-72.7% and an increase in the number of cellulose-destroying microorganisms. For all variants of the experiment, the activity of soil enzymes of the hydrolase and oxidoreductase classes was decreased.

Cavitation treatment as a means of modifying the antibacterial activity of various feed additives.

The quality of feed, including its microbiological characteristics, is important for the organization of full-value feeding of animals in agriculture. So, the means of non-reagent processing of feeds, including cavitation treatment, are becoming more widespread. In our study, it was shown that the amount of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM) decreases after a 5-min treatment of the test samples (chalk, fuz, bran, and zeolite) (1.1-35 times) compared to untreated samples, while an increase in the duration of exposure is proportional to the expression of the bactericidal effect. A study of the bioluminescent response of the test strain Escherichia coli K12 TG1 under the influence of the test samples showed inhibition of bioluminescence under the action of chalk and an increase in luminescence during incubation with fusa and bran. When examining the growth rates of strains E. Coli 675 and Bifidobacterium longum B379M, it was found that water and zeolite treated with cavitation suppressed the growth of E. coli 675, while the growth of Bifidobacterium longum B379M was higher than the control values at the end of the experiment. So, cavitation processing can cause the death of microflora of feed additives, at the same time, as a result of the dissociation of a complex of organic polymers, contributing to the positive response of probiotic strains. These studies can be used in agriculture in the preparation of feed additives from waste from the processing industry.

Assessment of biotoxicity of Cu nanoparticles with respect to probiotic strains of microorganisms and representatives of the normal flora of the intestine of broiler chickens.

Copper nanoparticle Cu (d = 55 ± 15 nm) and CuO nanoparticles (d = 90 ± 10 nm) were used in the studies (OOO Platina, Russia). Using the method of pure cultures, we extracted Lactobacillus, Enterococcus, and Enterobacterium from the intestines of broilers. Additionally, strains of Bacillus subtilis 10641 and Bifidobacterium were involved in probiotic strains. The data obtained in the course of the study testify to the insignificant biotoxicity of copper nanoparticles with respect to representatives of the genera Lactobacillus (30 to 15 µg/ml) and Bifidobacterium (30 µg/ml), with the most sensitive bacteria being the genus Lactobacillus, for which a concentration of 7.5 µg/ml was subinhibitory. The second stage was the study using method of agar wells. In the course of the experiment, we obtained results confirming the data of the research by the serial dilution method. In this case, as in the first case, the data indicate the insignificant biotoxicity of copper nanoparticles in relation to representatives of the genera Lactobacillus and Bifidobacterium. We have studied the bioaccumulating ability of microorganisms of the studied metals. In all the studies carried out, as in the first series of experiments, representatives of the genera Lactobacillus and Bifidobacterium with the lowest bioaccumulative ability were the most sensitive to copper nanoparticles and were 3.1 and 8.2%, respectively. The use of nanoparticles as a component of the fodder additive in small concentrations does not adversely affect not only the probiotic strains, but also the main representatives of the normoflora (Lactobacillus, Enterococcus, and Enterobacterium) of the poultry, the positive effect of the copper nanoparticles being directly related to low level of dissociation of nanoparticles, since biologically active ions will be released much more slowly, thereby creating a prolonged effect of exposure.

Effect of probiotics on the basis of Bacillus subtilis and Bifidobacterium longum on the biochemical parameters of the animal organism.

For the purpose of safe modulation of the intestinal microflora, probiotics have been increasingly used in recent years. In the present work, the effect of the probiotic sporobacterin (Bacillus subtilis 534) (I group) and soybean-bifidum (Bifidobacterium longum) (II group) on male rats of the Wistar line was evaluated. In assessing nonspecific immunity in vitro, there was an increase in the level of baseline level in the first and second groups (by 8.3 and 12.2% more control). The influence of probiotic preparations on the intestinal normoflora was assessed using PCR. Bifidumbacterin increased the normal microflora, in particular, Escherichia coli 1.55 times, Lactobacillus 1.26 times, Enterococcus 1.3 times as much control; the level of conditionally pathogenic microflora, in particular, Proteus spp. decreased by 1.3 times in comparison with the control. Sporobacterin also contributed to an increase in the amount of E. coli (1.55 times) and Lactobacillus (0.9 times). When a culture of Bifidobacterium longum was introduced, a selective reduction in the loss of chemical elements was observed against the background of the diet used. At the end of the experiment, the content of calcium in the body tissues of animals of group II exceeded this indicator in group I by 3.9%, phosphorus by 17.6%, copper by 28.5%, and zinc by 15.2%. The totality of the results obtained by us indicates that inclusion of Bifidumbacterium longum in the diet of animals makes the use of this preparation in the correction of mineral imbalance and improves the microflora of the intestines of animals by reducing the number of representatives of opportunistic microflora against the background of an increase in the number of basic representatives of normal microbiocenosis. Also, the use of probiotic drugs as additives leads to a slight increase in the level of nonspecific immunity, which increases the natural resistance of the organism.

The study of mechanisms of biological activity of copper oxide nanoparticle CuO in the test for seedling roots of Triticum vulgare.

The rapid development of nanotechnology raises questions assessment of their impact on living objects. In the present study, we evaluated the impact of nanoparticle (NP) CuO at concentrations ranging from 0.8 to 63.5 g/l in the test on wheat seedlings Triticum vulgare during 1-72 h. In the viability test (WST-test), cells were isolated from the roots of seedlings T. vulgare, 12 h not observed increase reductase activity after 24 h decreased rate of not more than 19% compared with the control. The number of dead cells in seedlings of T. vulgaris after exposure with CuO nanoparticles to the test with Evans blue increased by 5-15% compared to control. We observed that a significant increase in copper revenues leaves 4.5-8.9 times more in relation to the control and the roots-in 5-9.7 times. During the determined amount of active oxygen species, a significant proportional increase in the total pool of reactive oxygen species (ROS) in roots increased to 27.6% after exposure to NP CuO compared with the control. It is shown that in the introduction in medium, the NP CuO in the doses ranging from 3.2 to 63.5 g/l leads to DNA fragmentation and increases the fragments less than 3000 bp on 51.4-62.8%. The totality of our results influences nanoforms of copper oxide on the amount of ROS, and the viability of the genomic component of the cells shows different mechanisms of damage in the activation of a metabolic reaction, to determine the concentration of nano-CuO.