Antioxidant Defense and ROS Detoxification Enable Phenanthrene Tolerance in Nostoc calcicole ISC ۸۹

The accumulation of polycyclic aromatic hydrocarbons (PAHs) can adversely affect the environment and human health. Microalgae can remove and degrade PAHs. This study investigated microalgae responses to phenanthrene (PHE)-a representative PAH-focusing on antioxidant defense mechanisms associated with reactive oxygen species (ROS) detoxification and scavenging. This study examined biochemical responses, including soluble proteins and sugars, total lipids, enzymatic antioxidants, and malondialdehyde (MDA), in Nostoc calcicola ISC ۸۹, a phenanthrene-tolerant strain. The results showed that tolerance of N. calcicola ISC ۸۹ to PHE was associated with increased antioxidant enzyme activities, total lipid content, proline levels, and soluble sugars. The result showed that MDA and H۲O۲ contents decreased, while specific growth rate and dry weight increased in the tolerant species. This study provides new insights into the mechanisms underlying N. calcicola ISC ۸۹ tolerance to PHE-induced oxidative stress. Overall, these findings indicate that N. calcicola ISC ۸۹ mitigates PHE-induced oxidative damage by enhancing antioxidant defenses and ROS detoxification, thereby supporting growth and biomass accumulation under PAH stress.

کلیدواژه ها:

Phenanthrene ، Nostoc calcicola ، Antioxidant defense system ، ROS detoxification