Surfactants are extremely common organic compounds that enter the environment in large quantities in the form of household and industrial wastewater. The toxicity of surfactants for biological systems, the high concentration of substances and the duration of the bioremediation process of polluted ecosystems requires improving the biotechnology of microbial wastewater treatment for surfactants. The purpose of this work is to study the kinetic laws of the reaction of the biological decomposition of betaine surfactants. Pseudomonas bacteria were used as bio-destructors of the surfactants. Kinetic data were obtained to create the possibility of further optimization of research on the biodegradation of toxic organic substances. The strains that were promising destructors of cocamidopropylbetaine were selected. The toxicity of high concentrations of surfactants in relation to microorganisms of the genus Pseudomonas was proven. Safe values of the surfactant concentration for conducting biodegradation tests were found. A kinetic model of the biodestructive process was constructed. It proves that the processes of biodegradation are described by a kinetic equation of the first order. With the derived equation, it is possible to determine the time interval of biodegradation of cocamidopropylbetaine to the specified values by means of mathematical calculations.

Introduction. Infectious diseases remain a serious threat to humanity worldwide as bacterial pathogens grow more diverse. Bacteria, fungi, and parasites develop resistance to clinically approved antimicrobials, which reduces the efficacy of available drugs and treatment measures. As a result, there is an ever growing demand for new highly effective pharmaceuticals. This review describes mono- and polynuclear platinum and palladium complexes with antimicrobial properties. We compared several groups of antibacterial agents: antibiotics, antioxidant biologically active substances, antimicrobial nanoparticles, nanocomposite materials, biopolymers, micellar systems, and plant extracts. Study objects and methods. The review covered relevant articles published in Web of Science, Scopus, and Russian Science Citation Index for the last decade. The list of descriptors included such terms as mononuclear and binuclear complexes of platinum, palladium, and antimicrobial activity. Results and discussion. Chelates of platinum, palladium, silver, iridium, rhodium, ruthenium, cobalt, and nickel are popular therapeutic agents. Their antimicrobial activity against pathogenic microorganisms can be enhanced by increasing their bioavailability. Metalbased drugs facilitate the transport of organic ligands towards the bacterial cell. The nature of the ligand and its coordination change the thermodynamic stability, kinetic lability, and lipophilic properties of the complex, as well as the reactivity of the central atom. Polynuclear platinum and palladium complexes contain two or more bound metal (coordinate) centers. Covalent bonding with bacterial DNA enables them to form a type of DNA adducts, which is completely different from that of mononuclear complexes. Conclusion. Metal-based drugs with functional monodentate ligands exhibit a greater antimicrobial effect compared to free ligands. Poly- and heteronuclear complexes can increase the number of active centers that block the action of bacterial cells. When combined with other antibacterial agents, they provide a synergistic effect, which makes them a promising subject of further research.

One of the effective methods of cleaning up water is an adsorption method. The adsorption treatment is effectively used as a post-treatment after using treatment chemicals precipitators. You can use natural porous carbon-containing materials as obtained sorbents, as industrial waste, or cheap carbon raw modified by humans: ash, fines coconut, peat, activated carbon, active clay, bio- and phyto-sorbents, agricultural wastes (rice, barley, wheat husk, nutshells, bagasse, etc.). In this regard, there is a question of finding cheap natural sorbents with a high adsorption capacity. In this article we studied the regularity of extraction of heavy metal cations Cu2+, Co3+, Ni2+, Fe3+ from aqueous solutions, using natural sorbents: husk cedar cones, pine nut meal, walnut partitions, pectin. Constancy of the concentration of heavy metal ions in the solution corresponds to the time of adsorption equilibrium (from 10 to 40 minutes). High adsorption capacity with respect to heavy metal ions showed pectin and proteinaceous materials. It is shown that the adsorption capacity of natural raw materials in relation to heavy metal ions increases by 20-30% due to modification of the surface of biosorbents. The degree of metals extraction from solution using a composition based on a peel cedar cones and pectin increases by 20-30% in comparison with pure husk of a cedar cone. According to the degree of extraction from the aqueous solution, metal ions are arranged in the row Fe3+>Co3+>Ni2+>Cu2+.

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Effect of the concentration of surfactants differing in nature on the inhibition of the growth of microorganisms of the genus Pseudomonas putida was studied. All the surfactants inhibited the metabolic growth of microorganisms to various degrees. The results depended on the nature of the surfactants. For each surfactant, there is a range of concentrations characteristic of the growth or suppression of the growth of microorganisms. The values of the minimum inhibitory concentration and the growth inhibition zones diameters of the surfactants are compared. The highest antimicrobial activity belonged to the cationic Dimethylaminopropyl stearamide in relation to Pseudomonas putida

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Introduction. Pathogens keep evolving and develop resistance to antimicrobial drugs. As a result, science is constantly searching for new antimicrobial agents. Their complex forms based on organic and inorganic ligands exhibit a stronger synergistic antimicrobial effect, if compared to free ligands. The Scopus database contains 73 thousand scientific articles about antimicrobial activity descriptors published during the last five years. This selection includes ten thousand reviews and three thousand publications that feature the antimicrobial activity of platinum complexes. The research objective was to screen the antimicrobial properties of platinum nitrite complexes. The present paper highlights some of the current domestic and foreign trends in this field of research: the biochemical synthesis of peptides as metabolites of bacteria; the development of anti-biofilm agents that act on the protective systems of pathogens; the creation of antimicrobial nanosystems; the synthesis of antimicrobial surfactants; the synthesis and study of the antimicrobial activity of platinum complexes, etc. The authors also give a brief description of the mechanisms of antibacterial action. Study objects and methods. Five previously synthesized complexes of platinum (II) and platinum (IV), both mononuclear and bionuclear, were tested for antimicrobial activity. The platinum complexes contained terminal and bridged nitrite ligands. The test cultures included Bacillus subtilis and Aspergillus niger. The experiment involved the disk-diffusion method and the macro method of serial dilutions. Results and discussion. All the complexes inhibited the metabolic growth of microorganisms to various degrees. The results depended on the composition and structure of the complex, the number and charge of the coordination centers, the degree of platinum oxidation, and the thermodynamic stability and lability of ligand bonds with the complexing agent. The response to Aspergillus niger proved more pronounced. The Pt+2 nonelectrolyte complex containing both terminal and bridged nitrite ligands was less active than the Pt+2 cationic complex, which contained only bridged NO2– ligands. The highest antibacterial activity belonged to the bionuclear complex of PtIV-PtII [(NH3)2 (NO2)2PtIV(µ-NO2)2PtII(NH3)2](NO3)2 in relation to Bacillus subtilis B4647 and Aspergillus niger. The minimum inhibitory concentration (MIC) was > 125 μmol. Conclusion. The complexing resulted in a synergistic effect between the ligand and the complexing substance. The poly-core complexes contain two or more linked platinum centers that can covalently bind to DNA. They form a completely different type of DNA adducts compared to mononuclear complexes, as well as cross-links between DNA chains with fixation on different parts. The octahedral platinum complexes are kinetic and thermodynamically inert. Unlike similar squamous complexes, they proved to be able to act as prodrugs, recovering inside or outside the bacterial cell. The antimicrobial activity of the mixed-valence PtIV-PtII bionuclear complex [(NH3)2 (NO2)2PtIV(µ-NO2)2PtII(NH3)2](NO3)2 produced inhibitory effect comparable to the existing antimicrobial drugs. A further research will focus on composite mixtures of platinum complexes with other existing antimicrobial agents, as well as on other bacterial strains.