Project description:Nanoscale zero valent iron (nZVI) is used to remediate aquifers polluted by organochlorines or heavy metals has been also considered for elimination of harmful algal blooms. Highly reactive nZVI then affects microorganisms in the application area. To date, various nZVI toxicity endpoints have been studied on different organisms. However, the underlying mechanistic related to iron defense pathways have not been explained sufficiently. Here we aim to describe the physiological and transcriptomic response of the microalga, Raphidocelis subcapitata ATCC 22662, to 100 mg/L of non-reactive nFe3O4, and reactive nZVI. The combined effect of shading by nanoparticles and release of Fe2+ from nZVI posed a stronger inhibition leading to deformed cells and cytosol leakage in 15% of cells. Transcriptomic analysis confirmed the stronger physiological effect of nZVI (7,380 differentially expressed genes [DEGs]) than nFe3O4 (4,601 DEGs) after 1 h. nZVI (but not nFe3O4) caused increased DNA repair and replication, while deactivated carbohydrate-energy metabolisms, mitochondria signaling, and transmembrane ion transport. The defense response of algal cells was immediate to successfully face oxidative stress.
Project description:Green alga (Raphidocelis subcapitata) response to nanoscale zero valent iron (nZVI): The DNA damage repair pathways as sentinel response