title: Ammonia-Oligotrophic and Diazotrophic Heavy Metal-Resistant Serratia liquefaciens Strains from Pioneer Plants and Mine Tailings.
abstract: Mine tailings are man-made environments characterized by low levels of organic carbon and assimilable nitrogen, as well as moderate concentrations of heavy metals. For the introduction of nitrogen into these environments, a key role is played by ammonia-oligotrophic/diazotrophic heavy metal-resistant guilds. In mine tailings from Zacatecas, Mexico, Serratia liquefaciens was the dominant heterotrophic culturable species isolated in N-free media from bulk mine tailings as well as the rhizosphere, roots, and aerial parts of pioneer plants. S. liquefaciens strains proved to be a meta-population with high intraspecific genetic diversity and a potential to respond to these extreme conditions. The phenotypic and genotypic features of these strains reveal the potential adaptation of S. liquefaciens to oligotrophic and nitrogen-limited mine tailings with high concentrations of heavy metals. These features include ammonia-oligotrophic growth, nitrogen fixation, siderophore and indoleacetic acid production, phosphate solubilization, biofilm formation, moderate tolerance to heavy metals under conditions of diverse nitrogen availability, and the presence of zntA, amtB, and nifH genes. The acetylene reduction assay suggests low nitrogen-fixing activity. The nifH gene was harbored in a plasmid of ∼60 kb and probably was acquired by a horizontal gene transfer event from Klebsiella variicola.
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Lily X
authors.initials: LX
authors.lastname: Zelaya-Molina
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Hernández-Soto
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Jairo E
authors.initials: JE
authors.lastname: Guerra-Camacho
authors.affiliation: Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Monterrubio-López
authors.affiliation: Departamento de Botánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Patiño-Siciliano
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Villa-Tanaca
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala s/n. Col. Sto. Tomás, 11340, Mexico, D.F., Mexico. chdez38@hotmail.com.
authors.forename: César
authors.initials: C
authors.lastname: Hernández-Rodríguez
mesh_terms: D000641:Ammonia / Q000032:analysis*; D018441:Biofilms; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D014644:Genetic Variation; D006863:Hydrogen-Ion Concentration; D007210:Indoleacetic Acids / Q000032:analysis; D056186:Metagenomics; D019216:Metals, Heavy / Q000032:analysis*; D008800:Mexico; D008826:Microbial Sensitivity Tests; D008906:Mining; D009586:Nitrogen Fixation; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D044090:Serratia liquefaciens / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D012988:Soil Microbiology; D013312:Stress, Physiological
chemical_list: D004269:DNA, Bacterial; D007210:Indoleacetic Acids; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; C030737:indoleacetic acid; D000641:Ammonia
keywords: Ammonia-oligotrophic; Heavy metal resistance; Mine tailings; Nitrogen fixation; Serratia liquefaciens