A comparison of fate and toxicity of selenite, biogenically, and chemically synthesized selenium nanoparticles to zebrafish (Danio rerio) embryogenesis. Issue 1 (2nd January 2017)

• Record Type: Journal Article
• Authors: Mal, Joyabrata; Veneman, Wouter J.; Nancharaiah, Y. V.; van Hullebusch, Eric D.; Peijnenburg, Willie J. G. M.; Vijver, Martina G.; Lens, Piet N. L.
• Is Part Of: Nanotoxicology. Volume 11:Issue 1(2017)
• Page Start: 87
• Page End: 97
• Publication Date: 2017-01-02
• Subjects: Biogenic nanomaterials -- selenium bioremediation -- zebrafish -- EPS -- nanotoxicology; Toxicology -- Periodicals; 615.9
• DOI: 10.1080/17435390.2016.1275866
• Languages: English
• ISSNs: 1743-5390

Abstract

Abstract: Microbial reduction of selenium (Se) oxyanions to elemental Se is a promising technology for bioremediation and treatment of Se wastewaters. But a fraction of biogenic nano-Selenium (nano-Se b ) formed in bioreactors remains suspended in the treated waters, thus entering the aquatic environment. The present study investigated the toxicity of nano-Se b formed by anaerobic granular sludge biofilms on zebrafish embryos in comparison with selenite and chemogenic nano-Se (nano-Se c ). The nano-Se b formed by granular sludge biofilms showed a LC50 value of 1.77 mg/L, which was 3.2-fold less toxic to zebrafish embryos than selenite (LC50 = 0.55 mg/L) and 10-fold less toxic than bovine serum albumin stabilized nano-Se c (LC50 = 0.16 mg/L). Smaller (nano-Se cs ; particle diameter range: 25–80 nm) and larger (nano-Se cl ; particle diameter range: 50–250 nm) sized chemically synthesized nano-Se c particles showed comparable toxicity on zebrafish embryos. The lower toxicity of nano-Se b in comparison with nano-Se c was analyzed in terms of the stabilizing organic layer. The results confirmed that the organic layer extracted from the nano-Se b consisted of components of the extracellular polymeric substances (EPS) matrix, which govern the physiochemical stability and surface properties like ζ-potential of nano-Se b . Based on the data, it is contented that the presence of humic acid like substances of EPS on the surface of nano-Se b plays a major role in lowering the bioavailability (uptake) and toxicity of nano-Se b by decreasing the interactions between nanoparticles and embryos.