Aim: to determine the ability of neutrophilic sulfur-oxidizing bacteria to extract Cu (II) ions from aqueous solutions. Methods. The object of the study was the ability of marine sulfur-oxidizing bacteria isolated from the water of the Black Sea near the Odessa Bay to extract copper from aqueous solution. To study the metalaccumulating activity of sulfur-oxidizing bacteria, we have selected strains that were resistant to copper at the level of 0.01–0.02 mol/l. The initial concentration of Cu (II) in aqueous solution was 1 mM. The period of cultivation of microorganisms in aqueous solution containing copper was 10 days. The residual content of Cu (II) in aqueous solution was determined by the atomic absorption method on AAS-1 devices (Germany) and C-115PC Selmi (Ukraine) at the wavelength of 324.7 nm for Cu. The reliability of the results obtained was assessed on the Student's criterion with probability of p <0.05. Results. It was established that sulfur-oxidizing bacteria isolated from the water of the Black Sea capable of accumulating heavy metals from aqueous solutions, and Cu-accumulating activity depends on the duration of the interaction between microorganisms and solution. The maximum level of extraction of Cu (II) from aqueous solution was equal 89.24% was recorded on the 10th day of cultivation using a strain of Thiobacillus sp. DKZ_4. On the seventh day of cultivation, the extraction of Cu (II) from aqueous solution with using a strain of Thiobacillus sp. DKZ_2 reached 85.25%. It was shown that the level of resistance to copper, which had been previously defined, did not affect the ability of bacteria to accumulate copper. Conclusions. Neutral sulfur-oxidizing bacteria isolated from the water of the Black Sea are capable of extracting from aqueous solution from 22.83% to 89.24% of Cu (II) and therefore they can be used to develop biosorption biotechnology especially in the field of water purification from heavy metals. The ability to accumulate Cu depends on the strain, but does not depend on MIC.