Indicators of the Microbial Corrosion of Steel Induced by Sulfate-Reducing Bacteria Under the Influence of Certain Drugs

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.