Search Results (3)

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. Full article

Microbially influenced corrosion poses a significant threat to the integrity and longevity of carbon steel infrastructure, particularly in environments conducive to biofilm formation by thiosulfate-reducing bacteria (TRB) to carbon steel. This study explores the potential of Portulaca oleracea, an edible plant species, as a dual-action biocide and green corrosion inhibitor for mitigating MIC adhesion. Through a comprehensive suite of experimental and analytical techniques, including electrochemical analysis, microbial analysis, gravimetric methods, and surface characterization, the efficacy of Portulaca oleracea extract is evaluated for its ability to inhibit TRB growth and biofilm formation while concurrently providing corrosion protection to carbon steel substrates. The electrochemical analyses reveal the extract’s capacity with the anodic reaction inhibition achieving 80%, thereby reducing the overall corrosion rate of carbon steel in the presence of TRB biofilms. Complementary microbial analyses, such as viable cell counting using test kits, elucidate the biocidal action of the extract, effectively suppressing TRB growth and biofilm development, with the presence of 20 ppm of the extract reducing bacterial growth. Surface characterization techniques provide insights into the adsorption behavior of the extract’s constituents on the carbon steel surface, forming a protective film that mitigates corrosion and biofilm adhesion. The adsorption of the extract at the interface between mild steel and the formation water adheres to Langmuir isotherm. Overall, the biocorrosion issue we are addressing in this work is crucial for ensuring the sustainability and efficiency of equipment, pipelines, and other metal-based systems. Full article

The processes of microbial damage to materials lead to a number of environmental problems. To prevent the development of eco-trophic corrosively active groups of micro-organisms, “green” biocides/inhibitors are being developed. Actinobacteria of the genus Streptomyces are actively studied from the point of view of usefulness/harmfulness in relation to human activity, in particular, in the processes of microbial damage to materials. To summarize the results of available scientific research and reviews devoted to the participation and supposed mechanisms of structural materials damage caused by streptomycetes, the presented study was performed. The possible role of streptomycetes in the biodeterioration of structural materials was speculated. The obtained data indicate the need for further studies on streptomycetes as participants in the corrosion process, with special attention to their production of secondary metabolites and nanoparticles of metal and metal oxides with antimicrobial and inhibitory properties, which will contribute to the expansion of the list of “green” biocides/inhibitors. Full article