This paper tackles bacteria of the genus Bacillus as both biodamaging/biodegrading and biocontrolling agents. The article addresses the said bacteria’s ability to form biofilms and corrosive, antimicrobial and antibiofilm proactive compounds, primarily, siderophores. Their role depends on the species, microorganism strain, production of antimicrobial substances, biofilm formation, and the type of damaged material. The bacteria under analysis have demonstrated the ability to cause as well as inhibit biodamage. The involvement of bacteria of the genus Bacillus in microbiologically influenced corrosion processes is determined by the production of corrosive metabolites and the impact of certain bioelectrochemical mechanisms. Lipopeptides generated by Bacillus subtilis (surfactin, iturin and fengycin) are capable of modifying surfaces’ hydrophobic properties and impacting the microbes’ adhesion to surfaces. Produced by Bacillus velezensis, the siderophore bacillibactin at a high concentration is capable of inhibiting the formation of bacterial biofilms, thus slowing down the degradation of materials. Further study of siderophores as green inhibitors of microbiologically influenced corrosion may be promising as the said compounds possess antibiofilm-forming properties and high-intensity inhibitory capabilities.

Phytotesting has long been used to determine the quality of seeds, agricultural soil fertility, in biomedical research, and recently in the field of environmental protection to assess the ecological quality of natural environment (water, soil) in phytotesting of toxicants. Various plant representatives are used as model test organisms, in particular, onion (Allium cepa L.) is considered as a standard test plant for the determination of toxicants. The purpose of the work is to generalize methodological approaches of using onion (Allium cepa L.) in phytotesting of toxicants. Methodology. During the research, the following methods were used: 1) general scientific methods (methods of theoretical research of available information); 2) analytical and generalized methods (for the analysis of scientific and literature sources on the given problem); 3) empirical (for accumulating facts); 4) methods of argumentation (to prove one’s own judgments). Scientific novelty - methodical approaches of using onion in phytotesting of toxicants are summarized, formulas for calculating phytotoxic indices (root length index, phytotoxic effect of solutions, toxicity index of solutions for each test function, average toxicity index of the tested solutions) are presented. Conclusions - phytotesting is a commonly used method of assessing the quality of natural environment (water, soil) which is based on the sensitivity of plants to external chemical influences and is reflected in growth and morphological characteristics. The standard test plant for the determination of toxicant influence is the onion (Allium cepa), which can be used both in the growth test and in the Allium-test. The most sensitive characteristics of onion are the mitotic activity of the apical meristem cells and the frequency of cells with chromosomal aberrations.

Microbiological and genetic characteristics of Bacillus velezensis bacillibactinproducing strains and their effect on the sulfate-reducing bacteria biofilms on the poly(ethylene terephthalate) surface

Genotypic, physiological and biochemical features of Desulfovibrio strains in a sulfidogenic microbial community isolated from the soil of ferrosphere

The soil microbiome is involved in the processes of microbial corrosion, in particular, by the formation of biofilm. It has been proposed that an environmentally friendly solution to this corrosion might be through biological control. Bacillus velezensis NUChC C2b, Streptomyces gardneri ChNPU F3 and S. canus NUChC F2 were investigated as potentially ‘green’ biocides to prevent attachment to glass as a model surface and the formation of heterotrophic bacterial biofilm which participates in the corrosion process. Results showed high antagonistic and antibiofilm properties of S. gardneri ChNPU F3; which may be related to the formation of secondary antimicrobial metabolites by this strain. B. velezensis NUChC C2b and S. gardneri ChNPU F3 could be incorporated into green biocides – as components of antibiofilm agents that will protect material from bacterial corrosion or as agents that will prevent historical heritage damage.

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 %).