Screening of heavy metal-tolerant actinomycetes isolated from the Salí River

Fifty-three strains of actinomycetes resistant to heavy metals were isolated from the Sali River in northwest Argentina. Screening procedures that involve solid and liquid synthetic media containing Cd2+, Cu2+, or Hg2+ allowed the selection of six strains. These strains showed a quantitative sorption of Cd2+ and Cu2+ by more than 98% of the initial metal concentrations (0.1, 0.5, and 1.0 mM) tested.