title: Effects of C60 on the Salmonella typhimurium TA100 transcriptome expression: Insights into C60 -mediated growth inhibition and mutagenicity.
abstract: Rapid advances are being made in the creation and use of nanomaterials, but little is known about the impact these materials might have on key microbial functions if introduced into the environment. Previous studies have generated conflicting results with respect to the impact of fullerenes on microbial activity. In the present study, Salmonella typhimurium TA100 was selected as a model microbial system with which to investigate further the impact of C(60) aggregates on microbial growth, mutagenicity, and global transcript expression. Aggregates of C(60) predominantly less than 100 nm significantly impacted Salmonella growth at concentrations of ≥ 0.5 mg/L. In addition, C(60) aggregates also displayed mutagenic potential at concentrations ≥ 0.1 mg/L. Transcript expression analysis of S. typhimurium TA100 exposed to C(60) for 24 h indicated that 271 transcripts had significant differential expression relative to controls with twofold or more change. Of particular interest was the increased expression of transcripts coding for proteins involved in energy metabolism, amino acid biosynthesis, transcription, and DNA metabolism, and the decreased expression of transcripts coding for proteins involved in protein fate, transport, and binding and bacterial secretion systems. Collectively, these data indicate that C(60) interacts with the outer membrane of S. typhimurium TA100, resulting in delayed growth and mutagenicity, most likely by interfering with key transport functions and inducing a stress response, respectively.
authors.affiliation: U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, Mississippi, USA.
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Hancock
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Indest
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Gust
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Kennedy
mesh_terms: D037741:Fullerenes / Q000494:pharmacology*; D020869:Gene Expression Profiling; D009153:Mutagens / Q000494:pharmacology*; D053758:Nanoparticles; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D059467:Transcriptome
chemical_list: D037741:Fullerenes; D009153:Mutagens