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Sulfate-reducing bacteria (SRB) are widespread in various ecotopes despite their growth and enzymatic features not compared. In this study, the enzymatic parameters of ATP sulfurylase in cell-free extracts of sulfate-reducing bacteria isolated from various ecotopes such as soils, corrosion products and human large intestine were determined. Comparative analysis of both enzyme characteristics and growth parameters were carried out and similar research has not been reported yet. The initial and maximum rates of enzymatic reaction catalyzed by ATP sulfurylase were significantly different (p < 0.05) in the bacterial strains isolated from various environmental ecotopes. The specific activity of this enzyme in sulfate-reducing bacteria was determined for corrosive and intestinal strains 0.98-1.56 and 0.98-2.26 U × mg −1 protein, respectively. The Michaelis constants were 1.55-2.29 mM for corrosive and 2.93-3.13 mM for intestinal strains and the affinity range were demonstrated. Based on cluster analysis, the parameters of physiological and biochemical characteristics of sulfate-reducing bacteria from different ecotopes are divided into 3 clusters corresponding to the location of their isolation (soils, heating systems and human intestine). Understanding the enzymatic parameters of the initial stages of sulfate consumption in the process of dissimilatory sulfate reduction will allow the development of effective methods for controlling the production of toxic metabolites, including hydrogen sulfide.

A comparative study of the kinetic characteristics (specific activity, initial and maximum rate, and affinity for substrates) of key enzymes of assimilatory sulfate reduction (APS reductase and dissimilatory sulfite reductase) in cell-free extracts of sulphate-reducing bacteria (SRB) from various biotopes was performed. The material for the study represented different strains of SRB from various ecotopes. Microbiological (isolation and cultivation), biochemical (free cell extract preparation) and chemical (enzyme activity determination) methods served in defining kinetic characteristics of SRB enzymes. The determined affinity data for substrates (i.e., sulfite) were 10 times higher for SRB strains isolated from environmental (soil) ecotopes than for strains from the human intestine. The maximum rate of APS reductase reached 0.282–0.862 µmol/min×mg−1 of protein that is only 10 to 28% higher than similar initial values. The maximum rate of sulfite reductase for corrosive relevant collection strains and SRB strains isolated from heating systems were increased by 3 to 10 times. A completely different picture was found for the intestinal SRB Vmax in the strains Desulfovibrio piger Vib-7 (0.67 µmol/min × mg−1 protein) and Desulfomicrobium orale Rod-9 (0.45 µmol/min × mg−1 protein). The determinant in the cluster distribution of SRB strains is the activity of the terminal enzyme of dissimilatory sulfate reduction—sulfite reductase, but not APS reductase. The data obtained from the activity of sulfate reduction enzymes indicated the adaptive plasticity of SRB strains that is manifested in the change in enzymatic activity.

Currently, a lot of researcher’s attention is devoted to the problem of microbiologically influenced corrosion (MIC), since it causes huge damages to the economy, initiating the destruction of oil and gas pipelines and other underground constructions. To protect industrial materials from MIC effects an organic chemical inhibitors are massively used. However, the problem of their use is associated with toxicity, dangerous for the environment that caused the need for development the alternative methods of MIC repression. At the review, the data about different types of inhibitors-biocides usage has provided. The chemical inhibitors features are given and the mechanisms of their protective action are considered. The screening results and use of alternative and eco-friendly methods for managing the effect of corrosion caused by sulfate-reducing bacteria (SRB) are highlighted. Methods of joint application of chemical inhibitors and enhancers, such as chelators, biosurfactants, which contribute to reducing the concentration of chemical inhibitors, are discussed. The possibility of disruption of the quorum sensing interaction in the bacterial community to prevent the biofilm formation is considered. The information about the use of natural plant extracts, food waste, as well as by-products of agro-industrial production to combat MIC is provided. The development of biological corrosion control methods (to combat MIC) is of great importance for creating the best alternative and eco-friendly approaches to managing the effect of corrosion caused by SRB. The analysis of the literature data indicates the need to find the best alternatives and environmentally friendly solutions.

to study the microbial communities and sulfate-reducing bacteria of soils collected from the surfaces of the gas-pipeline. Methods: microbiological, biochemical, molecular biological. Results: In the microbial communities of soils near the main-gas pipeline "Soyuz" (Ivano-Frankivsk region, Ukraine) were appeared such microorganisms as iron-reducing, tionic denitrifying, ammonifying, denitrifying and diazotrophic bacteria among them were dominated sulfate-reducing bacteria. It were obtained 4 pure cultures of the sulfate-reducing bacteria and was determined culturalmorphological and physiological-biochemical characteristics of bacteria. In the fatty acid components of sulfate-reducing bacteria were identified 14 fatty acids with chain length from C10 to C18. According to partial sequence of the 16S rRNA gene the K1 isolate has 90% homology with the sequence of Desulfovibrio desulfuricans ATCC 27774 (NR074858.1), K2 isolate-92% homology with Desulfovibrio sp. D4 (AF192155) K1/3 isolate has 95% homology with Desulfotomaculum kuznetsovii DSM 6115 (CP002770.1). Conclusion: According to the phenotypic, chemotaxonomic and molecular genetic characteristics bacteria isolated from soils near main-gas pipeline were related to the genera Desulfovibrio, Desulfotomaculum.