Biotechnological Potential of Newly Isolated Microalga Strain in Cu and Cr Biosorption from Single and Bimetallic Systems

The contamination of water by heavy metals is among the main ecological challenges of society due to industrialization and urbanization. To overcome this issue, various treatment processes have been developed. Phycoremediation is considered a promising strategy offering advantages in terms of cost-effectiveness. The present work aims to investigate the cellular responses of an isolated green microalga strain (Chlamydomonas sp.) to chromium (Cr) and copper (Cu) exposure in single and bimetallic systems. At ½ IC50 concentration, the metal removal efficiencies were reported: up to 58.11 ± 0.979% for Cu and 41.4 ± 0.870% for Cr in single systems. When both metals were combined, Cr removal efficiency improved to 57.71 ± 0.832%, whereas Cu removal efficiency showed minimal variation, reaching 58.43 ± 1.059%. Furthermore, Cu and Cr appeared to have a negative effect on cell growth and photosynthetic pigment accumulation. An enhancement in lipid content for microalgae cells after Cu and/or Cr exposure, particularly C14:0, C16:0, C20:0, C18:0, C16:1, C18:1, and C20:1, as well as polysaccharides, was detected, whereas the protein content decreased. FTIR analysis showed that several functional groups could be involved in the phycoremediation process.