title: Extra and intracellular synthesis of nickel oxide nanoparticles mediated by dead fungal biomass.
abstract: The use of dead biomass of the fungus Hypocrea lixii as a biological system is a new, effective and environmentally friendly bioprocess for the production and uptake of nickel oxide nanoparticles (NPs), which has become a promising field in nanobiotechnology. Dead biomass of the fungus was successfully used to convert nickel ions into nickel oxide NPs in aqueous solution. These NPs accumulated intracellularly and extracellularly on the cell wall surface through biosorption. The average size, morphology and location of the NPs were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The NPs were mainly spherical and extra and intracellular NPs had an average size of 3.8 nm and 1.25 nm, respectively. X-ray photoelectron spectroscopy analysis confirmed the formation of nickel oxide NPs. Infrared spectroscopy detected the presence of functional amide groups, which are probable involved in particle binding to the biomass. The production of the NPs by dead biomass was analyzed by determining physicochemical parameters and equilibrium concentrations. The present study opens new perspectives for the biosynthesis of nanomaterials, which could become a potential biosorbent for the removal of toxic metals from polluted sites.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Marcia Regina
authors.initials: MR
authors.lastname: Salvadori
authors.affiliation: Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Rômulo Augusto
authors.initials: RA
authors.lastname: Ando
authors.affiliation: Departamento de Engenharia Química, Politécnica, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Cláudio Augusto Oller
authors.initials: CA
authors.lastname: Nascimento
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
mesh_terms: D000327:Adsorption; D018533:Biomass; D005110:Extracellular Space / Q000737:chemistry*; D035901:Hypocrea / Q000302:isolation & purification / Q000378:metabolism*; D042541:Intracellular Space / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D009532:Nickel / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D009532:Nickel; C028007:nickel monoxide