Influence of algal-extracellular polymeric substances (EPS) on the pristine and combined toxicity of TiO2 NPs and PSNPs in Artemia salina: Eco-corona enhances the toxic effects
Lokeshwari Natarajan, M. Annie Jenifer, Amitava Mukherjee
Abstract
The study on the influence of Natural Organic Matter (NOM) over the individual and combined effects of different nanomaterials on marine species is pertinent. The current study explores the role of Extracellular Polymeric Substances (EPS) in influencing the individual and combined toxic effects of polystyrene nanoplastics (PSNPs) viz. aminated (NH 2 -PSNPs), carboxylated (COOH-PSNPs), and plain PSNPs and TiO 2 NPs in the marine crustacean, Artemia salina . A. salina was interacted with pristine PSNPs, pristine TiO 2 NPs, EPS incubated PSNPs, EPS incubated TiO 2 NPs, binary mixture of PSNPs and TiO 2 NPs, and EPS adsorbed binary mixture of PSNPs and TiO 2 NPs for 48 h. The present study proves that, when compared to the pristine toxicity of PSNPs and TiO 2 NPs, the coexposure of TiO 2 NPs with PSNPs resulted in increased toxicity. The adsorption of algal EPS on the NMs (both in their pristine and combined forms) significantly increased the toxic nature of the NMs against A. salina . It was observed that with an increase in the hydrodynamic diameter of the particles, the mortality, oxidative stress, and ingestion of the NMs by A. salina increased. The uptake of Ti by A. salina from 8 mg/L TiO 2 NPs, EPS adsorbed 8 mg/L TiO 2 NPs, 8 mg/L TiO 2 NPs + NH 2 -PSNPs and the EPS adsorbed mixture of 8 mg/L TiO 2 NPs, 8 mg/L TiO 2 NPs + NH 2 -PSNPs was observed to be 0.043, 0.047, 0.186, and 0.307 mg/g of A. salina . The adsorption of algal EPS on the NMs (both in their pristine and combined forms) significantly increased the toxic nature of the NMs against A. salina . The major outcomes from the current study highlight the role of EPS in exacerbating the toxicity of NMs in marine crustaceans. • EPS adsorption on nanomaterials increased the mortality in Artemia salina. • EPS adsorption over NMs showed both antagonistic and synergistic effects in A. salina. • Adsorption of EPS on the NMs was time and concentration (NMs) dependent. • EPS adsorption on NMs elevated oxidative damage and lipid peroxidation in A. salina. • EPS adsorption on NMs increased the Ti uptake in A. salina.