Green solutions: evaluating the impact of Chlorella sorokiniana and Anabaena laxa on captan phycoremediation

This study explores the use of algae for phycoremediation, focusing on how Chlorella sorokiniana and Anabaena laxa detoxify water contaminated with captan, a common fungicide. The efficiency of these species in absorbing captan and the associated biochemical changes were evaluated to assess their potential for environmental protection. Microalgae were exposed to captan concentrations of 15 and 30 mg/L, and various parameters, including captan uptake, chlorophyll (Chl) a, carotenoid levels, and changes in metabolic profiles (soluble carbohydrates, organic acids, amino acids, and fatty acids), were measured. Results showed Anabaena had a higher captan absorption capacity (141.7 µg/g at 15 mg/L and 239.3 µg/g at 30 mg/L) compared to Chlorella (74.43 µg/g and 162 µg/g). Increased captan uptake reduced the growth of both species, as indicated by lower Chl a levels. Both species accumulated osmo-protectants and antioxidants as defense mechanisms, with soluble sugars increasing by 83.49% in Chlorella and 68.87% in Anabaena, and carotenoids increasing by 60.42% and 46.24%, respectively. Principal component analysis revealed distinct species-level responses, with Anabaena showing greater tolerance. The study concludes that both species can effectively remediate captan, with Anabaena being more efficient, indicating their potential for mitigating agrochemical impacts in aquatic environments and promoting sustainable agriculture and water management.