title: Effect of metal sulfide pulp density on gene expression of electron transporters in Acidithiobacillus sp. FJ2.
abstract: In Acidithiobacillus ferrooxidans, one of the most important bioleaching bacterial species, the proteins encoded by the rus operon are involved in the electron transfer from Fe2+to O2. To obtain further knowledge about the mechanism(s) involved in the adaptive responses of the bacteria to growth on the different uranium ore pulp densities, we analyzed the expression of the four genes from the rus operon by real-time PCR, when Acidithiobacillus sp. FJ2 was grown in the presence of different uranium concentrations. The uranium bioleaching results showed the inhibitory effects of the metal pulp densities on the oxidation activity of the bacteria which can affect Eh, pH, Fe oxidation and uranium extractions. Gene expression analysis indicated that Acidithiobacillus sp. FJ2 tries to survive in the stress with increasing in the expression levels of cyc2, cyc1, rus and coxB, but the metal toxicity has a negative effect on the gene expression in different pulp densities. These results indicated that Acidithiobacillus sp. FJ2 could leach the uranium even in high pulp density (50%) by modulation in rus operon gene responses.
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran. ffatemi@aeoi.org.ir.
authors.forename: Faezeh
authors.initials: F
authors.lastname: Fatemi
authors.affiliation: Department of Biotechnology, Faculty of Life Science, Alzahra University, Tehran, Iran.
authors.forename: Saba
authors.initials: S
authors.lastname: Miri
authors.affiliation: Department of Microbiology, Faculty of Science, Qom Branch, Islamic Azad University, Qom, Iran.
authors.forename: Samaneh
authors.initials: S
authors.lastname: Jahani
mesh_terms: D042763:Acidithiobacillus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D004579:Electron Transport; D005296:Ferrous Compounds / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics*; D009876:Operon; D010084:Oxidation-Reduction; D013440:Sulfides / Q000378:metabolism; D014501:Uranium / Q000633:toxicity*
chemical_list: D001426:Bacterial Proteins; D005296:Ferrous Compounds; D026901:Membrane Transport Proteins; D013440:Sulfides; D014501:Uranium
keywords: A. ferrooxidans; Bioleaching; Real-time PCR; rus operon genes