Toxicity of Nickel Oxide Nanoparticles on a Freshwater Green Algal Strain ofChlorella vulgaris

Abstract

A freshwater microalga strain of Chlorella vulgaris was used to investigate toxic effects induced by nickel oxide nanoparticles (NiO-NPs) in suspension. Algal cells were exposed during 96 h to 0–100 mg L−1 of NiO-NPs and analyzed by flow cytometry. Physicochemical characterization of nanoparticles in tested media showed a soluble fraction (free Ni2+) of only 6.42% for 100 mg L−1 of NiO-NPs, indicating the low solubility capacity of these NPs. Toxicity analysis showed cellular alterations which were related to NiO-NPs concentration, such as inhibition in cell division (relative cell size and granularity), deterioration of the photosynthetic apparatus (chlorophyll synthesis and photochemical reactions of photosynthesis), and oxidative stress (ROS production). The change in cellular viability demonstrated to be a very sensitive biomarker of NiO-NPs toxicity with EC50 of 13.7 mg L−1. Analysis by TEM and X-ray confirmed that NiO-NPs were able to cross biological membranes and to accumulate inside algal cells. Therefore, this study provides a characterization of both physicochemical and toxicological properties of NiO-NPs suspensions in tested media. The use of the freshwater strain of C. vulgaris demonstrated to be a sensitive bioindicator of NiO-NPs toxicity on the viability of green algae.

Eco-Friendly Bioemulsifier Production by Mucor circinelloides UCP0001 Isolated from Mangrove Sediments Using Renewable Substrates for Environmental Applications

“…The microalgae was cultured in BG-11 liquid medium at pH 7 under white light and 12-12 h photoperiod (light/dark), room temperature 25 • C, constant aeration for 168 h. Aliquots (10 mL) of 10 6 cells/mL in the exponential phase were inoculated into vials containing 0.1%, 0.5%, and 1% of the bioemulsifier. Chemical surfactant (Triton X100) was tested at the same concentrations for positive control and BG-11 liquid medium was used as negative control [14].…”

Graphene-based materials do not impair physiology, gene expression and growth dynamics of the aeroterrestrial microalga Trebouxia gelatinosa

“…Green microalgae have frequently been used as target organisms for testing the toxicity of different types of nanoparticles (Bondarenko et al 2013;Suppi et al 2015;Roy et al 2016;Oukarroum et al 2017). Some studies, based mostly on short-term exposure (Pretti et al 2014;Nogueira et al 2015;Tang et al 2015), have actually focused on the effects of GBMs, but no consistent toxicity trends can be inferred.…”

Study on the Antagonistic Potential of Biosynthesized Hematite Nanoparticles During Water and Wastewater Treatment

“…by Dash et al, where AgNPs caused fragmentation and subsequent disintegration of chloroplasts. Other cytotoxicity features such as deterioration in algal cell division and severe alternations in enzyme activity were observed in C. vulgaris by exposure to NiO‐NPs …”

“…Other cytotoxicity features such as deterioration in algal cell division and severe alternations in enzyme activity were observed in C. vulgaris by exposure to NiO-NPs. [52] On the other hand, the respective control remained green and flourished well in the culture medium. Remarkably, two-fold augmentation of C. vulgaris biomass was observed following the application of IS.…”