title: Molecular stress responses to nano-sized zero-valent iron (nZVI) particles in the soil bacterium Pseudomonas stutzeri.
abstract: Nanotoxicological studies were performed in vitro using the common soil bacterium Pseudomonas stutzeri to assess the potentially toxic impact of commercial nano-sized zero-valent iron (nZVI) particles, which are currently used for environmental remediation projects. The phenotypic response of P. stutzeri to nZVI toxicity includes an initial insult to the cell wall, as evidenced by TEM micrographs. Transcriptional analyses using genes of particular relevance in cellular activity revealed that no significant changes occurred among the relative expression ratios of narG, nirS, pykA or gyrA following nZVI exposure; however, a significant increase in katB expression was indicative of nZVI-induced oxidative stress in P. stutzeri. A proteomic approach identified two major defence mechanisms that occurred in response to nZVI exposure: a downregulation of membrane proteins and an upregulation of proteins involved in reducing intracellular oxidative stress. These biomarkers served as early indicators of nZVI response in this soil bacterium, and may provide relevant information for environmental hazard assessment.
authors.affiliation: Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain ; Moncloa Campus of International Excellence, Madrid, Spain.
authors.forename: Maria Ludovica
authors.initials: ML
authors.lastname: Saccà
authors.affiliation: Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Fajardo
authors.affiliation: Proteomic Facility, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Martinez-Gomariz
authors.affiliation: Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Costa
authors.affiliation: Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Nande
authors.affiliation: Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: Martin
mesh_terms: D002374:Catalase / Q000235:genetics; D007501:Iron / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D018384:Oxidative Stress; D010316:Particle Size; D040901:Proteomics; D044223:Pseudomonas stutzeri / Q000187:drug effects* / Q000201:enzymology; D012988:Soil Microbiology
chemical_list: D007501:Iron; D002374:Catalase