title: Qualitative toxicity assessment of silver nanoparticles on the fresh water bacterial isolates and consortium at low level of exposure concentration.
abstract: Silver nanoparticles (AgNPs) pose a high risk of exposure to the natural environment owing to their extensive usage in various consumer products. In the present study we attempted to understand the harmful effect of AgNPs at environmentally relevant low concentration levels (≤1ppm) towards two different freshwater bacterial isolates and their consortium. The standard plate count assay suggested that the AgNPs were toxic towards the fresh water bacterial isolates as well as the consortium, though toxicity was significantly reduced for the cells in the consortium. The oxidative stress assessment and membrane permeability studies corroborated with the toxicity data. The detailed electron microscopic studies suggested the cell degrading potential of the AgNPs, and the FT-IR studies confirmed the involvement of the surface groups in the toxic effects. No significant ion leaching from the AgNPs was observed at the applied concentration levels signifying the dominant role of the particle size, and size distribution in bacterial toxicity. The reduced toxicity for the cells in the consortium than the individual isolates has major significance in further studies on the ecotoxicity of the AgNPs.
authors: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors: Deepak
authors: D
authors: Kumar
authors: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors: Jyoti
authors: J
authors: Kumari
authors: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors: Sunandan
authors: S
authors: Pakrashi
authors: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors: Swayamprava
authors: S
authors: Dalai
authors: Department of Materials Engineering, Indian Institute of Science, Bangalore, India; Department of Chemical Technology, University of Johannesburg, Johannesburg, South Africa.
authors: Ashok M
authors: AM
authors: Raichur
authors: Bioproducts Laboratory, CSIR-Central Leather Research Institute, Chennai, India.
authors: T P
authors: TP
authors: Sastry
authors: Bioproducts Laboratory, CSIR-Central Leather Research Institute, Chennai, India.
authors: A B
authors: AB
authors: Mandal
authors: Centre for Nanobiotechnology, VIT University, Vellore, India.
authors: N
authors: N
authors: Chandrasekaran
authors: Centre for Nanobiotechnology, VIT University, Vellore, India. Electronic address: amit.mookerjea@gmail.com.
authors: Amitava
authors: A
authors: Mukherjee
mesh_terms: D002463:Cell Membrane Permeability / Q000187:drug effects; D005618:Fresh Water / Q000382:microbiology; D053768:Metal Nanoparticles / Q000633:toxicity*; D059013:Microbial Consortia / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D012834:Silver / Q000633:toxicity*; D017550:Spectroscopy, Fourier Transform Infrared; D018675:Toxicity Tests
chemical_list: D012834:Silver
keywords: AgNP; Bacteria; Consortium; Freshwater; Toxicity