Isolation and characterization of heavy metal tolerant microalgae from old mining areas of Saxony

Heavy metal contamination poses a major threat to ecosystems and human health, particularly in mining-impacted areas. Algal biosorption offers a promising, low-cost, and sustainable approach to mitigate this problem. In this study, five microalgal strains were bioprospected and isolated from abandoned mining sites and evaluated for their tolerance and ability to remove Cu, Cd, and Cr(VI) from aqueous solutions. Laboratory experiments were performed to assess heavy metal tolerance and biosorption efficiency under controlled conditions. The results demonstrated that isolates Chlorella vulgaris RG1-4 and Tetradesmus obliquus Ehr33-9 exhibited the highest tolerance and biosorption capacity for Cu, with removal efficiencies of 100.00 mg/g and 89.73 mg/g, respectively. The isolate Lobochlamys segnis Ehr31-1 showed the highest tolerance and biosorption capacity for Cd, reaching 93.17 mg/g. These findings highlight the potential of locally adapted microalgal strains as effective biosorbents for remediating heavy metal-contaminated water sources.