Green Synthesized ZnO Nanoparticles Mediated by Streptomyces plicatus: Characterizations, Antimicrobial and Nematicidal Activities and Cytogenetic Effects

Zinc oxide nanoparticles (ZnO-NPs) are regarded as one of the most promising kinds of materials in a variety of fields, including agriculture. Therefore, this study aimed to biosynthesize and characterize ZnO-NPs and evaluate their different biological activities. Seven isolates of actinomycetes were obtained and screened for ZnO-NPs synthesis. The isolate MK-104 was chosen and identified as the Streptomyces plicatus MK-104 strain. The biosynthesized ZnO-NPs exhibited an absorbance peak at 350 nm and were spherical in shape with an average size of 21.72 ± 4.27 nm under TEM. XRD and DLS methods confirmed these results. The biosynthesized ZnO-NPs demonstrated activity against plant pathogenic microbes such as Erwinia amylovora, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Fusarium moniliform and Alternaria alternata, with MIC values ranging from 15.6 to 500 µg/mL. Furthermore, ZnO-NPs had a significant effect on Meloidogyne incognita, with death percentages of 88.2, 93.4 and 96.72% after 24, 48 and 72 h of exposure, respectively. Vicia faba seeds were treated with five concentrations of ZnO-NPs (12.5, 25, 50, 100 and 200 µg/mL). Low-moderate ZnO-NP concentrations (12.5–50 µg/mL) were shown to promote seed germination and seedling development, while the mitotic index (MI) decreased as the dosage of ZnO-NPs increased. Micronuclei (MNs) and the chromosomal abnormality index increased as well.

CYTOGENETIC CONSEQUENCES OF THE MIXED EFFECTS OF OPISTORCHIASIS AND TICK-BORNED ENCEPHALITIS IN ASSOCIATION WITH POLYMORPHISM BY GLUTHATHIONE-S-TRANSFERASE GENES

Purpose: to study the duration of the preservation of the cytogenetic effects of tickborne encephalitis (TBE) in individuals infected with the Opisthorchis felineus (OF) helminth, which differ in alleles of the glutathione-S-transferase enzyme genes. Methods: the objects of the study were patients with tick-borne encephalitis in whom the frequencies of micronucleated lymphocytes were detected. All examined patients were subdivided into two groups: TBE patients non-infected with OF, and TBE patients infected with OF. Multiplex PCR was used to analyze the GSTM1 and GSTT1 genes. Results: patients with TBE, infected with OF, had a significantly lower increase in the level of cytogenetic disorders than patients with TBE without OF infection; at the same time, the restoration of the cytogenetic norm in this group was not reached, and there was no association between the frequency of micronucleated lymphocytes and different variants of the glutathione-S-transferase enzyme genes. Conclusion: the frequency of cytogenetic changes in TBE patients infected with OF are significantly less than one in patients with TBE without OF infection. Polymorphism in the genes of the enzyme glutathione-S-transferase does not have significant effect on the cytogenetic disorders in patients with TBE with OF infection.

LONG-TERM GENETIC AND EPIGENETIC DISORDERS IN PERSONS EXPOSED TO IONIZING RADIATION AND THEIR DESCENDANTS (review)

The review is devoted to long-term genetic and epigenetic disorders in exposed individuals and their descendants, namely to cytogenetic effects in the Chornobyl NPP accident clean-up workers and their children, DNA methylation as an epigenetic modification of human genome. Data presented in review expand the understanding of risk of the prolonged exposure for the present and future generations, which is one of key problems posed by fundamental radiation genetics and human radiobiology. The Scientific Council meeting of NAMS approved the NRCRM Annual Report. Key words: Chornobyl NPP accident, cytogenetic effects, DNA methylation.