title: Enzymatic formation of gold nanoparticles by submerged culture of the basidiomycete Lentinus edodes.
abstract: We report for the first time that the medicinal basidiomycete Lentinus edodes can reduce Au(III) from chloroauric acid (HAuCl4) to elemental Au [Au(0)], forming nanoparticles. Several methods, including transmission electron microscopy, electron energy loss spectroscopy, X-ray fluorescence, and dynamic light scattering, were used to show that when the fungus was grown submerged, colloidal gold accumulated on the surface of and inside the mycelial hyphae as electron-dense particles mostly spherical in shape, with sizes ranging from 5 to 50nm. Homogeneous proteins (the fungal enzymes laccase, tyrosinase, and Mn-peroxidase) were found for the first time to be involved in the reduction of Au(III) to Au(0) from HAuCl4. A possible mechanism forming Au nanoparticles is discussed.
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia.
authors.forename: Elena P
authors.initials: EP
authors.lastname: Vetchinkina
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia. Electronic address: loshchinina@yandex.ru.
authors.forename: Ekaterina A
authors.initials: EA
authors.lastname: Loshchinina
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia.
authors.forename: Andrey M
authors.initials: AM
authors.lastname: Burov
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia.
authors.forename: Lev A
authors.initials: LA
authors.lastname: Dykman
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia.
authors.forename: Valentina E
authors.initials: VE
authors.lastname: Nikitina
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002712:Chlorides / Q000737:chemistry / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D006046:Gold / Q000737:chemistry* / Q000378:metabolism*; D017612:Gold Compounds / Q000737:chemistry / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D014442:Monophenol Monooxygenase / Q000378:metabolism; D010316:Particle Size; D020942:Shiitake Mushrooms / Q000737:chemistry / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*
chemical_list: D002712:Chlorides; D005656:Fungal Proteins; D017612:Gold Compounds; D006046:Gold; C024568:gold tetrachloride, acid; D014442:Monophenol Monooxygenase
keywords: Extracellular and intracellular synthesis; Gold nanoparticles; Lentinus edodes; Phenol oxidases; Reduction mechanisms