title: Biosynthesis of gold nanoparticles by the extreme bacteriumDeinococcus radioduransand an evaluation of their antibacterial properties.
abstract: Deinococcus radioduransis an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability ofD. radioduransto reduce Au(III) and biosynthesize gold nanoparticles (AuNPs) was investigated in aqueous solution by ultraviolet and visible (UV/Vis) absorption spectroscopy, electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS).D. radioduransefficiently synthesized AuNPs from 1 mM Au(III) solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III) may be reduced to Au(I), and further reduced to Au(0) with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria by damaging their cytoplasmic membrane. Therefore, the extreme bacteriumD. radioduranscan be used as a novel bacterial candidate for efficient biosynthesis of AuNPs, which exhibited potential in biomedical application as an antibacterial agent.
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Jiulong
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Qinghao
authors.initials: Q
authors.lastname: Li
authors.affiliation: Central Laboratory, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China.
authors.forename: Xiaoqiong
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Bing
authors.initials: B
authors.lastname: Tian
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Jiangliu
authors.initials: J
authors.lastname: Yu
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Shang
authors.initials: S
authors.lastname: Dai
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Weng
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University.
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Hua
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D034301:Deinococcus / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects; D006046:Gold / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D053768:Metal Nanoparticles; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D006046:Gold
keywords: Deinococcus radiodurans; antibacterial; gold ions; gold nanoparticles; reduction