Insights into the growth and biochemical defense responses associated with fenitrothion toxicity and uptake by freshwater cyanobacteria

Seham M Hamed; Marwa Yousry A Mohamed; Badriah Saleh Alammari; Hamada AbdElgawad

doi:10.1016/j.chemosphere.2024.141909

Insights into the growth and biochemical defense responses associated with fenitrothion toxicity and uptake by freshwater cyanobacteria

Chemosphere. 2024 Apr 7:358:141909. doi: 10.1016/j.chemosphere.2024.141909. Online ahead of print.

Authors

Seham M Hamed¹, Marwa Yousry A Mohamed², Badriah Saleh Alammari², Hamada AbdElgawad³

Affiliations

¹ Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P. O. Box: 90950, Riyadh 11623, Kingdom of Saudi Arabia; Soil Microbiology Department, Soils, Water and Environment Research Institute, Agricultural Research Center, Giza, P.O. 175 El‒Orman, Egypt. Electronic address: SMmhamed@imamu.edu.sa.
² Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), P. O. Box: 90950, Riyadh 11623, Kingdom of Saudi Arabia.
³ Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt; Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium.

PMID: 38593960
DOI: 10.1016/j.chemosphere.2024.141909

Abstract

The extensive use of fenitrothion (FNT) in agricultural practices induces its persistence in soil and waterways. Therefore, it is essential to implement effective management practices such as using cyanobacteria for FNT removal and accumulation, particularly under accidental contamination. To this end, we evaluated the responses of two freshwater cyanobacteria taxa, Nostoc muscorum and Anabaena laxa to mild (7.5 mg L^-1) and high (15 mg L^-1) levels of FNT over a period of 7 d. Compared to N. muscorum, A. laxa was more tolerant to FNT, exhibiting higher FNT uptake and removal efficiencies at mild (16.3%) and high (17.5%) levels. FNT induced a dose-dependent decrease in cell growth, Chl a, phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase/oxygenase activities, which were more pronounced in N. muscorum. Moreover, FNT significantly increased oxidative damage markers i.e., increased lipid peroxidation (MDA), protein oxidation, H₂O₂ levels and NADPH oxidase enzyme activity, to more extent in N. muscorum. Compared to N. muscorum, A. laxa had high antioxidant capacity (FRAP), glutathione and increased activities of glutathione-S-transferase, glutathione reductase, glutathione peroxidase and superoxide dismutase, suggesting a robust antioxidant defense mechanism to mitigate FNT toxicity. However, N. muscorum devoted the induction of ascorbate content and the activity of catalase, peroxidase, monodehydroascorbate reductase, ascorbate peroxidase, and dehydroascorbate reductase enzymes. Although A. laxa had greater intracellular FNT, it experienced less FNT-induced oxidative stress, likely due to over production of antioxidants. Consequently, A. laxa is considered as a promising candidate for FNT phycoremediation. Our findings provide fundamental information on species-specific toxicity of FNT among cyanobacteria and the environmental risk of FNT toxicity in aquatic environments.

Keywords: Antioxidants; Bioremoval; Cyanobacteria; Fenitrothion; Oxidative stress; Photosynthesis.