Author(s): Barros, Diana ; Pradhan, Arunava ; Mendes, Vera M. ; Manadas, Bruno ; Santos, P. M. ; Pascoal, Cláudia ; Cássio, Fernanda
Date: 2019
Persistent ID: http://hdl.handle.net/1822/72985
Origin: RepositóriUM - Universidade do Minho
Project/scholarship: info:eu-repo/grantAgreement/FCT/5876/147364/PT;
Subject(s): Ciências Naturais::Ciências Biológicas; Engenharia e Tecnologia::Biotecnologia Ambiental; Science & Technology
The increased use of silver nanoparticles (AgNPs) raises concerns about their impacts on aquatic ecosystems. The impacts of Ag+ and AgNPs were assessed on proteomic and antioxidant enzymatic responses of Pseudomonas sp. M1. The effects of Ag+ on bacterial growth were stronger than those of AgNPs (EC20 = 107.1 μg L−1 for Ag+; EC20 = 307.2 μg L−1 for AgNPs), indicating the lower toxicity of the latter. At EC20, the activities of antioxidant enzymes increased more under exposure to Ag+ than to AgNPs, particularly for superoxide dismutase and glutathione peroxidase (stimulation of 667% and 433%, respectively). A total of 166 proteins were identified by SWATH-MS; among these, only 59 had their content significantly altered by one or both forms of silver. Exposure to AgNPs resulted in an increase of about 54% of these proteins, whereas 54% decreased under exposure to Ag+. Gene Ontology enrichment analysis revealed that protein folding and transmembrane transport were the most relevant processes affected by Ag+ exposure, whereas AgNPs mostly affected translation. Also, results suggest that each form of silver induced different adaptive responses. Furthermore, the low levels of Ag+ released from AgNPs (<0.1%) support a minor role of dissolved silver in AgNP toxicity to Pseudomonas sp. M1
ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) and by the Portuguese Foundation for Science and Technology I.P. (FCT) through the strategic funding UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569), PTDC/AAC-AMB/121650/2010, POCI-01-0145-FEDER-007440 (ref. UID/NEU/04539/2013), the National Mass Spectrometry Network (RNEM) under the contract POCI-01-0145-FEDER402-022125 (ref. ROTEIRO/0028/2013), and PTDC/BIA-BMA/ 30922/2017
