title: Bacterial tolerance to silver nanoparticles (SNPs): aeromonas punctata isolated from sewage environment.
abstract: Use of silver nanoparticles (SNPs) is increasing in a large number of consumer products. Thus, the possible build-up of the nanoparticles in the environment is becoming a major concern. Aeromonas punctata isolated from sewage showed tolerance to 200 μg/ml SNPs. The growth kinetics data for A. punctata treated with nanoparticles were similar to those in the absence of nanoparticles. There was a reduction in the amount of exopolysaccharides (EPS) in bacterial culture supernatant after nanoparticle-supernatant interaction. EPS capping of the nanoparticles was confirmed by UV-visible, XRD and comparative FTIR analysis. The EPS-capped SNPs showed less toxicity to Escherichia coli, Staphylococcus aureus and Micrococcus luteus compared to the uncapped ones. The study suggests capping of nanoparticles by bacterially produced EPS as a probable physiological defense mechanism.
authors.affiliation: Nanobio-Medicine Laboratory, School of Bio-Sciences and Technology, VIT University, Vellore, India.
authors.forename: S
authors.initials: S
authors.lastname: Sudheer Khan
authors.forename: E
authors.initials: E
authors.lastname: Bharath Kumar
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
authors.forename: N
authors.initials: N
authors.lastname: Chandrasekaran
mesh_terms: D000333:Aeromonas / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D012722:Sewage / Q000382:microbiology*; D012834:Silver / Q000737:chemistry* / Q000633:toxicity; D013056:Spectrophotometry, Ultraviolet; D014961:X-Ray Diffraction
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D012834:Silver