title: High-throughput bioaccumulation, biotransformation, and production of silver and selenium nanoparticles using genetically engineered Pichia pastoris.
abstract: A genetically modified Pichia pastoris strain overexpressing a metal-resistant variant of cytochrome b5 reductase enzyme was developed for silver and selenium biosorption and for nanoparticle production. The maximum recombinant enzyme expression level was approximately 31 IU/ml in the intercellular fluid after 24 h of incubation, and the capacity of the recombinant biomass for the biosorption of silver and selenium in aqueous batch models were measured as 163.90 and 63.71 mg/g, respectively. The ions were reduced in the presence of enzyme, leading to the formation of stable 70-180 nm metal nanoparticles. Various instrumental analyses confirmed the well-dispersed and crystalline nature of the spherical nanometals. The purified silver and selenium nanoparticles exhibited at least 10-fold less cytotoxicity toward HDF, EPG85-257, and T47D cells than silver nitrate and selenium dioxide. These results revealed that the engineered Pichia strain is an eco-friendly, rapid, high-throughput, and versatile reduction system for nanometal production.
authors: Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran.
authors: Fatemeh
authors: F
authors: Elahian
authors: Department of Genetics, Faculty of Basic Sciences, University of Shahrekord, Shahrekord, Iran.
authors: Somayeh
authors: S
authors: Reiisi
authors: Department of Medical Biotechnology, School of Medicine, Zanjan University of Medical Sciences, Iran.
authors: Arman
authors: A
authors: Shahidi
authors: Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran. Electronic address: mirzaei.a@skums.ac.ir.
authors: Seyed Abbas
authors: SA
authors: Mirzaei
mesh_terms: D001711:Biotransformation; D042966:Cytochrome-B(5) Reductase / Q000235:genetics* / Q000378:metabolism; D005818:Genetic Engineering / Q000379:methods*; D057166:High-Throughput Screening Assays / Q000379:methods; D007218:Industrial Microbiology / Q000379:methods; D053758:Nanoparticles / Q000378:metabolism* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D010843:Pichia / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D012643:Selenium / Q000378:metabolism*; D012834:Silver / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D012834:Silver; D042966:Cytochrome-B(5) Reductase; D012643:Selenium
keywords: Biosorption; Cytochrome b5 reductase; Heavy metals; Nanoparticle; Recombinant yeast