Pleurotus strains with remediation potential to remove toxic metals from Doce River contaminated by Samarco dam mine

The disaster caused by the rupture of the Samarco tailings dam affected several Brazilian cities and created environmental and economic problems for the Doce River basin. For this reason, the aim of this study was to investigate the use of Pleurotus strains in the removal of toxic metals from the water of the Doce River. Aluminium, arsenic, barium, beryllium, bismuth, cadmium, caesium, lead, cobalt, copper, chromium, indium, iron, lithium, magnesium, manganese, mercury, nickel, silver, selenium, strontium, thallium, uranium, vanadium and zinc in Doce River water samples were quantified by inductively coupled plasma mass spectrometry. Three Pleurotus strains were tested for their capacity to remove potentially toxic metals from these water samples. In addition, Ames test was performed to verify the mutagenic potentials of these samples. Initially, the Doce River water samples showed high concentrations of aluminium, arsenic, barium, lead, iron, magnesium and manganese. But, the analyses from the batch system indicated that Pleurotus efficiently reduced lead (97%), iron (96%), aluminium (95%), manganese (92%), arsenic (87%) and barium (61%). The Ames test indicated that water samples treated with the fungal strains showed decreased mutagenicity. Studies on the contact time effect showed that the peak metal elimination was achieved between 12 and 24 h after fungal inoculation for most of the metals evaluated with a tendency to stabilize during the subsequent period for the elements aluminium, arsenic, barium, iron and lead. Thus, the results indicate that these Pleurotus strains have a biotechnological potential in bioremediation of contaminated or degraded sites.

Automated summary

The study aimed to investigate the potential of Pleurotus strains in removing toxic metals from the water of the Doce River. Results showed that the Pleurotus efficiently reduced lead, iron, aluminium, manganese, arsenic, and barium concentrations in the water samples, while also decreasing the mutagenicity of the samples. Studies on contact time effect revealed that peak metal elimination was achieved within 12 to 24 hours after fungal inoculation for most metals, indicating the biotechnological potential of these Pleurotus strains in bioremediation.