Dimethyl sulfoxide (DMSO) is widely used as an industrial solvent and for a variety of medical purposes. Reports of the toxicity of DMSO to living organisms vary. The plants Lepidium sativum L. and Raphanus raphanistrum subsp. sativus (L.) Domin. are widely used in the biotesting of toxicants. Currently, there is no information on the phytotoxicity of aqueous solutions of DMSO for these test plants, which determined the aim of this study. Methodology. Phytotoxicity of aqueous DMSO solutions was assessed using a growth test. The following plants were used as test plants: 1) seed radish (R. raphanistrum subsp. sativus) of the French breakfast variety, 10 seeds of which were placed in a Petri dish on filter paper moistened with distilled water (control) or 0.5 %, 1.0 %, 5.0 %, 10.0 %, 25.0 % or 45.0 % aqueous solution of DMSO (experiment); 2) watercress (L. sativum) of the Aphrodite variety, 10 seeds of which were placed in a Petri dish on filter paper moistened with distilled water (control) or a 0.025 %, 0.05 % or 0.1 % aqueous solution DMSO (experiment). The research was carried out in triplicate for 6 days (radish) and 5 days (watercress), during which the energy of seed germination of test plants (%) was determined on the 3rd day, on the 6th day (radish) and on the 5th day (watercress) – seed germination (%) and biometric and morphometric indicators of test plant seedlings (root and aerial part length, mm). Scientific novelty. In a growth test with R. raphanistrum subsp. sativus showed extreme phytotoxicity for 5.0-45.0 % aqueous DMSO solutions and no phytotoxicity for 0.025-1.0 % aqueous DMSO solutions in a growth test with L. sativum and R. raphanistrum subsp. sativus. Conclusions. Aqueous solutions of DMSO in concentrations of 0.025-1.0 % did not show phytotoxic properties according to the growth test with L. sativum and R. raphanistrum subsp. sativus, in contrast to 5.0-45.0 % solutions, which showed extreme phytotoxicity according to the growth test with R. raphanistrum subsp. sativus. The obtained results indicate that this substance will not inhibit plant growth at concentrations found in wastewater (0.05-0.08 %).

Microorganisms cause microbiologically influenced corrosion, for the prevention of which bactericide inhibitors are used. The aim of the work was to study in vitro the sensitivity of SRB Desulfovibrio oryzae NUChC SRB1 to different concentrations of dimethyl sulfoxide (DMSO), and evaluate the indicators of the microbial corrosion of steel induced by this bacterium in the presence of the pharmaceutical drugs DMSO and paracetamol. The sensitivity of SRB D. oryzae to 1–100% DMSO (v/v) was studied via the dilution method in Postgate’s “C” liquid medium. The corrosion activity of D. oryzae against steel 3 was investigated under DMSO and paracetamol treatment at a final concentration of 45% (v/v) and 0.2% (w/v), respectively, according to the ability of bacteria to form a biofilm on the surface of the steel samples (via the crystal violet method) and the effect on the corrosion rate (via the gravimetric method). It was revealed that DMSO affected D. oryzae NUChC SRB1 and exhibited bactericidal properties (at a concentration range of 10–100%, v/v) and antibiofilm properties (at a concentration of 45%, v/v). Despite its antibiofilm properties confirmed by the reduction in bacterial biofilm mass, anticorrosion features were not observed in the model 35-day conditions of the microbial corrosion of steel in an anaerobic environment with bacterial sulfate reduction. Paracetamol (0.2%, w/v) did not affect biofilm formation by SRB under these conditions, and significantly contributed to an increase in the rate of the microbial corrosion of steel. The prospect of further research is to assess the effect of DMSO and paracetamol on the indicators of microbial corrosion induced by SRB under the influence of the concentrations of these compounds found in wastewater, to clarify the possible additional causes of damage to the equipment of treatment plants. Further research should also be directed at investigating the antimicrobial properties of complexes of compounds with DMSO, which should be considered as an ecological solution to the problem of microbiologically influenced corrosion prevention.

The search for new growth-regulating compounds remains a relevant research direction in view of the issue of food security. Previously, a number of thiazolyl acetic acid derivatives have been synthesized, which are promising biologically active compounds according to their physicochemical characteristics. The aim of this work was to study the growth-regulating properties of both previously and newly synthesized thiazolyl acetic acid derivatives using a growth phytotest with Lepidium sativum and Sinapis alba. This study was carried out under laboratory conditions of phytotesting growth indicators of test plants of the class Dicotyledones—L. sativum and S. alba under the influence of 10 μg/mL, 100 μg/mL, and 1000 μg/mL aqueous solutions of the compounds with a comparative analysis of the action of the active components of Rhizopon^TM and herbicide benazolin. It was found that, exhibiting high herbicidal properties at a concentration of 1000 μg/mL (primarily the compound with a benzothiazole fragment), the studied thiazolyl acetic acid derivatives with decreasing concentration (100 μg/mL and 10 μg/mL) reduce phytotoxicity to its complete elimination against L. sativum and S. alba for the compound 2-[2-(N-tert-butoxycarbonyl)-aminoethyl-1,3thiazol-4-yl]acetic acid (compound 3), as well as against L. sativum for the compound 5-phenylthiazol-2-yl acetic acid (compound 5). A weak stimulating effect on the length of the above-ground part of S. alba seedlings was recorded for 2-[2-(3,3,3-trifluoropropyl)-1,3thiazol-4-yl]acetic acid (compound 1) and 2-[2-(N-tert-butoxycarbonyl)-aminoethyl-1,3thiazol-4-yl]acetic acid (compound 3) at their concentration of 10 μg/mL; however, an improvement in the vitality index under the action of these compounds was not observed. The results obtained in this study indicate the biological activity of both previously and newly synthesized thiazolyl acetic acid derivatives, namely their growth-regulatory properties, expanding knowledge about promising herbicidal compounds with a possible hormetic effect, which requires further research.

Microorganisms take an active part in the processes of microbiologically influenced corrosion, which is protected against by using bactericides—often toxic compounds—with inhibitory properties. There are many studies of eco-friendly “green” biocides/inhibitors, in particular those based on microbial metabolites. Indicators for the processes of microbial corrosion of steel 3 induced by the sulfate-reducing bacteria Desulfovibrio oryzae NUChC SRB2 under the influence of the strains Bacillus velezensis NUChC C2b and Streptomyces gardneri ChNPU F3 have not been investigated, which was the aim of this study. The agar well diffusion method (to determine the antibacterial properties of the supernatants) was used, along with the crystal violet (to determine the biomass of the biofilm on the steel) and gravimetric methods (to determine the corrosion rate). A moderate adhesiveness to steel 3 was established for D. oryzae due to its biofilm-forming ability. The presence of a supernatant on cultures of S. gardneri, B. velezensis and their mixture (2:1) did not reduce the biofilm-forming properties of D. oryzae. Compared to the control, a decrease in the corrosion rate was recorded for the variant of the mixture of the studied bacterial culture supernatants. This indicates the potential of this mixture for use in corrosion protection in environments with sulfate-reducing bacteria, which requires further research.