title: Characterization of a copper-resistant symbiotic bacterium isolated from Medicago lupulina growing in mine tailings.
abstract: A root nodule bacterium, Sinorhizobium meliloti CCNWSX0020, resistant to 1.4 mM Cu2+ was isolated from Medicago lupulina growing in mine tailings. In medium supplied with copper, this bacterium showed cell deformation and aggregation due to precipitation of copper on the cell surface. Genes similar to the copper-resistant genes, pcoR and pcoA from Escherichia coli, were amplified by PCR from a 1.4-Mb megaplasmid. Inoculation with S. meliloti CCNWSX0020 increased the biomass of M. lupulina grown in medium added 0 and 100 mg Cu2+ kg(-1) by 45.8% and 78.2%, respectively, and increased the copper concentration inside the plant tissues grown in medium supplied with 100 μM Cu2+ by 39.3%, demonstrating that it is a prospective symbiotic system for bioremediation purposes.
authors.affiliation: College of Life Sciences, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A & F University, Yangling, Shaanxi 712100, China.
authors.forename: Lian-Mei
authors.initials: LM
authors.lastname: Fan
authors.forename: Zhan-Qiang
authors.initials: ZQ
authors.lastname: Ma
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Liang
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Li
authors.forename: En-Tao
authors.initials: ET
authors.lastname: Wang
authors.forename: Ge-Hong
authors.initials: GH
authors.lastname: Wei
mesh_terms: D000327:Adsorption / Q000187:drug effects; D001673:Biodegradation, Environmental / Q000187:drug effects; D019295:Computational Biology; D003198:Computer Simulation; D003300:Copper / Q000302:isolation & purification / Q000633:toxicity*; D005798:Genes, Bacterial / Q000235:genetics; D007700:Kinetics; D029902:Medicago / Q000187:drug effects / Q000254:growth & development* / Q000382:microbiology*; D008855:Microscopy, Electron, Scanning; D008906:Mining; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016962:Sinorhizobium meliloti / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013559:Symbiosis / Q000187:drug effects*; D013696:Temperature; D013997:Time Factors; D014866:Waste Products / Q000032:analysis*
chemical_list: D012336:RNA, Ribosomal, 16S; D014866:Waste Products; D003300:Copper