title: Assessing environmental drivers of microbial communities in estuarine soils of the Aconcagua River in Central Chile.
abstract: Aconcagua River basin (Central Chile) harbors diverse economic activities such as agriculture, mining and a crude oil refinery. The aim of this study was to assess environmental drivers of microbial communities in Aconcagua River estuarine soils, which may be influenced by anthropogenic activities taking place upstream and by natural processes such as tides and flood runoffs. Physicochemical parameters were measured in floodplain soils along the estuary. Bacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Pseudomonas, Bacillus and Fungi were studied by DGGE fingerprinting of 16S rRNA gene and ribosomal ITS-1 amplified from community DNA. Correlations between environment and communities were assessed by distance-based redundancy analysis. Mainly hydrocarbons, pH and the composed variable copper/arsenic/calcium but in less extent nitrogen and organic matter/phosphorous/magnesium correlated with community structures at different taxonomic levels. Aromatic hydrocarbons degradation potential by bacterial community was studied. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenases genes were detected only at upstream sites. Naphthalene dioxygenase ndo genes were heterogeneously distributed along estuary, and related to Pseudomonas, Delftia, Comamonas and Ralstonia. IncP-1 plasmids were mainly present at downstream sites, whereas IncP-7 and IncP-9 plasmids showed a heterogeneous distribution. This study strongly suggests that pH, copper, arsenic and hydrocarbons are main drivers of microbial communities in Aconcagua River estuarine soils.
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center of Nanotechnology and Systems Biology & Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, 2390123 Valparaíso, Chile.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Fuentes
authors.affiliation: Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), 38116 Braunschweig, Germany College of Resources and Environmental Sciences, China Agricultural University, 100193 Beijing, China.
authors.forename: Guo-Chun
authors.initials: GC
authors.lastname: Ding
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center of Nanotechnology and Systems Biology & Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, 2390123 Valparaíso, Chile.
authors.forename: Franco
authors.initials: F
authors.lastname: Cárdenas
authors.affiliation: Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), 38116 Braunschweig, Germany.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Smalla
authors.affiliation: Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Center of Nanotechnology and Systems Biology & Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, 2390123 Valparaíso, Chile michael.seeger@usm.cl.
authors.forename: Michael
authors.initials: M
authors.lastname: Seeger
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002677:Chile; D049308:Dioxygenases / Q000235:genetics; D063366:Estuaries; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D059013:Microbial Consortia; D009097:Multienzyme Complexes / Q000235:genetics; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D045483:Rivers / Q000382:microbiology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; D049308:Dioxygenases; C038703:naphthalene dioxygenase
keywords: 16S rRNA gene; Aconcagua River; DGGE; IncP plasmid; PAH-RHD gene; microbial community