A presence of microscopic fungi, heterotrophic bacteria, as well as neutrophilic and acidophilic chemolitotrophic bacteria was determined in coal microbiocenosis. The largest and most active towards pyrite sulfur removal is the Acidithiobacillus genus. Heterotrophic bacteria have the biggest potential when it comes to removal of organic sulfur. Preceding treatment of coal with “silicate” bacteria from the Bacillus genus will allow to use coal microbiocenosis for its biodesulfurisation at its full potential.

The results of Acidithiobacillus ferrooxidans strains genetic variability studies that were first isolated from waste by coal and energy industries of Ukraine are reported in this article. These strains, according to the results of previous studies, are fully consistent with the biological properties of A. ferrooxidans bacteria given in Bergey’s Manual of Determinative Bacteriology and other original works [8, 10, 12, 18] also strains studied, regardless of habitat, were resistant to temperature and pH, had a mixed type of food, similar energy sources used by strains, etc. [1, 10, 11]. Using PCR was confirmed the affiliation of isolated from different of origin dumps of acidophilic chemolithotrophic strains with A. ferrooxidans. Genetic polymorphism of the strains was studied by RAPD-PCR using universal primer M13. It was shown that strains of A. ferrooxidans that were isolated from various dumps have a wide genetic diversity. By PCR, their affiliation with the species A. ferrooxidans was confirmed. Comparison analysis of the obtained RAPD profiles showed the variability of the strains which coincides with their main phenotypic properties, as described earlier [11]. The most heterogeneous profiles were characteristic of A. ferrooxidans DTV 1, A. ferrooxidans Lad 5 and A. ferrooxidans Lad 27. The obtained RAPD profiles served as the basis for the generation of the dendrogram constructed using the Neighbor-Joining method and calcula­ting the similarity matrix, based on the coefficient of similarity of Nei & Li. Based on the obtained dendrogram, the formation of two clusters that combine similar strains is shown. The obtained indicators of the probability of formation of nodes of the constructed dendrogram range from 65.0 to 76.0 %%, which confirms the high degree of similarity between strains grouped by clusters. It is also shown that the first of the cluster includes strains that were isolated from coal and waste from its enrichment, and the second cluster includes strains that were isolated from coal waste. The obtained data confirm that the genetic variability of the strains depends on the primary location of isolation of the strains, and the coefficients of similarity between them varies from 0.182 to 0.80.