Sensitivity of pathogenic bacteria strains to treated mine water

Mine water as a result of meteoric and/or underground water’s contact with tailings
and underground workings could have an elevated content of metals associated with sulfate, often
acidic, due to the bio-oxidation of sulfides. When entering aquatic ecosystems, the mine water can
cause significant changes in the species’ trophic levels, therefore a treatment is required to adjust the
alkalinity and to remove the heavy metals and metalloids. The conventional mine water treatment
removes metals, but in many cases it does not reduce the sulfate content. This paper aimed to
predict the impact of conventionally treated mine water on the receiving river by assessing the
genotoxic activity on an engineered Escherichia coli and by evaluating the toxic effects generated
on two Gram-negative bacterial strains, Pseudomonas aeruginosa and Escherichia coli. Although the
main chemical impact is the severe increases of calcium and sulfate concentrations, no significant
genotoxic characteristics were detected on the Escherichia coli strain and on the cell-viability with a
positive survival rate higher than 80%. Pseudomonas aeruginosa was more resistant than Escherichia coli
in the presence of 1890 mg SO42−/L. This paper reveals different sensitivities and adaptabilities of
pathogenic bacteria to high concentrations of sulfates in mine waters.