PJB-2022-347
Antioxidative defense systems in two scenedesmus species exposed to copper and lead
Yasar Aluç
Abstract
Heavy metals, including copper (Cu) and lead (Pb) depending on species, differentially affect algal growth and metabolism. Scenedesmus obliquus (S. obl), and Scenedesmus regularis (S. reg) are known to be affected by these environmental changes. Changes in the growth rates, level of oxidative stress markers, and antioxidants were analyzed following exposure to various concentrations of Cu (32, 44, 272, and 476 µM) and Pb (6, 8.4, 12.1, and 18.1 µM) for 25 days. Compared to the control groups, chlorophyll a amounts were low in the studied species. In addition, a consistent decrease in chlorophyll a level was detected depending on the applied stress doses, but it was not found to be statistically significant. Total antioxidant levels increased significantly in the dosage and concentration-dependent manners in both species when exposed only to Pb. The molecular antioxidant ratios in both species were higher, which was significant for total flavonoids. While the increase in SOD activity of the species against both metal stresses was observed at 18.1 µM Pb concentration (9.5%) in S. regularis, it was detected at 476 µM Cu concentration (13.2%) in S. obliquus. A similar situation was observed in GR activity at a Pb concentration of 12.1 µM (40.5%) in S. regularis, while it was at 476 µM Cu concentration (18.5%) in S. obliquus. Thus, the data indicate that the studied algae species exhibited similar strategies to alleviate long-term metal toxicity. This study also provided new data for Cu and Pb removal efficiency abilities of two microalgae species, where metals uptake and efficient antioxidant defense system protected species against oxidative stress induced by metals stress.
To Cite this article:
Aluç, Y. 2023. Antioxidative defense systems in two scenedesmus species exposed to copper and lead. Pak. J. Bot., 55(6): DOI: http://dx.doi.org/10.30848/PJB2023-6(41)
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