Silver nanocrystallites: biofabrication using Shewanella oneidensis, and an evaluation of their comparative toxicity on gram-negative and gram-positive bacteria.

摘要: Microorganisms have long been known to develop resistance metal ions either by sequestering metals inside the cell or effluxing them into extracellular media. Here we report biosynthesis of silver-based single nanocrystallites well-defined composition and homogeneous morphology utilizing γ-proteobacterium, Shewanella oneidensis MR-1, upon incubation with aqueous silver nitrate solution. Further characterization these particles revealed that crystals consist small, reasonably monodispersed spheres in 2−11 nm size range (average 4 ± 1.5 nm). The bactericidal effect nanoparticles (biogenic-Ag) is compared chemically synthesized (colloidal-Ag oleate capped nanoparticles, oleate-Ag) assessed using Gram-negative (E. coli S. oneidensis) Gram-positive (B. subtilis) bacteria. Relative toxicity was based on diameter inhibition zone disk diffusion tests, minimum inhibitory concentrations, live/dead a...