Assessment of Antibiotic Resistance Genes in Soils Polluted by Chemical and Technogenic Ways with Poly-Aromatic Hydrocarbons and Heavy Metals

Anthropogenic activities are leaving lots of chemical footprints on the soil. It alters the physiochemical characteristics of the soil thereby modifying the natural soil microbiome. The prevalence of antimicrobial-resistance microbes in polluted soil has gained attention due to its obvious public health risks. This study focused on assessing the prevalence and distribution of antibiotic-resistance genes in polluted soil ecosystems impacted by industrial enterprises in southern Russia. Metagenomic analysis was conducted on soil samples collected from polluted sites using various approaches, and the prevalence of antibiotic-resistance genes was investigated. The results revealed that efflux-encoding pump sequences were the most widely represented group of genes, while genes whose products replaced antibiotic targets were less represented. The level of soil contamination increased, and there was an increase in the total number of antibiotic-resistance genes in proteobacteria, but a decrease in actinobacteria. The study proposed an optimal mechanism for processing metagenomic data in polluted soil ecosystems, which involves mapping raw reads by the KMA method, followed by a detailed study of specific genes. The study's conclusions provide valuable insights into the prevalence and distribution of antibiotic-resistance genes in polluted soils and have been illustrated in heat maps.

Arsenic Removal of Contaminated Soils by Phytoremediation of Vetiver Grass, Chara Algae and Water Hyacinth

This research has been carried out for assessing phytoremediation of contaminated soils with 4 concentrations of arsenic by three plants, namely Vetiver grass (Vetiveria zizanioides), Chara algae (Chara vulgaris) and Water hyacinth (Hyacintus orientalis). The experimental results showed that at least two sampling times were significantly different. In addition, at least two plants were also significantly different in terms of percentages of total arsenic that were removed from the soil of the pots, as well as significant interactions between plant and arsenic concentrations. The results obtained from the thermodynamic studies show that, obtained by zero Gibbs free-energy, the process reached an equilibrium on the 60th day of the experiment, and, in fact, the adsorption of arsenic after the 60th day would be negligible.