Laboratoire de Génie Enzymatique et Microbiologie, Equipe Biotechnologie des Algues, Ecole Nationale D'Ingénieurs de Sfax, Université de Sfax, Sfax, Tunisia.
Laboratoire de Biotechnologies Végétales Appliquées à l'Amélioration des Cultures, Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia; Laboratory of Plant Physiology-Department of Biology, Universidad Autónoma Madrid, Darwin 2, ES28049, Madrid, Spain.
Chemosphere. 2024 Sep;364:143133. doi: 10.1016/j.chemosphere.2024.143133. Epub 2024 Aug 20.
Microalgae have gained recognition as versatile candidates for the remediation of heavy metals (HMs). This study investigated the biosorption potential of Dunaliella sp. AL1 for copper (Cu(II)) and hexavalent chromium (Cr(VI)) in aqueous solutions. The marine microalga Dunaliella sp. AL1 was exposed to half-sublethal concentrations of both metals in single and bimetallic systems, and responses in algal growth, oxidative stress, photosynthetic pigment production, and photosynthetic performance were evaluated. Cu and/or Cr exposure increased the generation of reactive oxygen species (ROS) in microalgae cells but did not impact algal growth. In terms of photosynthesis, there was a decrease in chlorophylls and carotenoids production in the microalgae culture treated with Cr, either alone or in combination with Cu. The study recorded promising metal removal efficiencies: 26.67%-20.11% for Cu and 94.99%-95.51% for Cr, in single and bimetallic systems, respectively. FTIR analysis revealed an affinity of Cu and Cr ions towards aliphatic/aldehyde C-H, N-H bending, and phosphate groups, suggesting the formation of complex bonds. Biochemical analysis of microalgae biomass collected after the removal of Cr alone or in combination with Cu showed a significant decrease in total carbohydrate content and soluble protein levels. Meanwhile, higher lipid accumulation was recorded and evidenced by BODIPY 505/515 staining. Fatty acid composition analysis by GC revealed a modulation in lipid composition, with a decrease in the ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA), in response to Cu, Cr, and Cu-Cr exposure, indicating the suitability of the biomass for sustainable biofuel production.
微藻已被公认为修复重金属（HM）的多功能候选物。本研究调查了杜氏盐藻 AL1 对铜（Cu（II））和六价铬（Cr（VI））在水溶液中的生物吸附潜力。将海洋微藻杜氏盐藻 AL1 暴露于两种金属的半致死浓度的单一和双金属系统中，并评估了藻类生长、氧化应激、光合色素产生和光合作用性能的反应。Cu 和/或 Cr 暴露会增加微藻细胞中活性氧（ROS）的产生，但不会影响藻类生长。就光合作用而言，在用 Cr 处理的微藻培养物中，叶绿素和类胡萝卜素的产生减少，无论是单独使用还是与 Cu 联合使用。研究记录了有希望的金属去除效率：在单一和双金属系统中，Cu 为 26.67%-20.11%，Cr 为 94.99%-95.51%。FTIR 分析表明 Cu 和 Cr 离子对脂肪族/醛 C-H、N-H 弯曲和磷酸盐基团具有亲和力，表明形成了复杂的键。单独去除 Cr 或与 Cu 联合去除后收集的微藻生物质的生化分析表明，总碳水化合物含量和可溶性蛋白水平显着下降。同时，记录到更高的脂质积累，并通过 BODIPY 505/515 染色证明。GC 分析的脂肪酸组成表明，响应 Cu、Cr 和 Cu-Cr 暴露，脂质组成发生调制，不饱和脂肪酸（UFA）与饱和脂肪酸（SFA）的比例降低，表明生物质适合可持续生物燃料生产。
