title: Molecular analysis of enrichment cultures of ammonia oxidizers from the Salar de Huasco, a high altitude saline wetland in northern Chile.
abstract: We analyzed enrichment cultures of ammonia-oxidizing bacteria (AOB) collected from different areas of Salar de Huasco, a high altitude, saline, pH-neutral water body in the Chilean Altiplano. Samples were inoculated into mineral media with 10 mM NH4+ at five different salt concentrations (10, 200, 400, 800 and 1,400 mM NaCl). Low diversity (up to three phylotypes per enrichment) of beta-AOB was detected using 16S rDNA and amoA clone libraries. Growth of beta-AOB was only recorded in a few enrichment cultures and varied according to site or media salinity. In total, five 16S rDNA and amoA phylotypes were found which were related to Nitrosomonas europaea/Nitrosococcus mobilis, N. marina and N. communis clusters. Phylotype 1-16S was 97% similar with N. halophila, previously isolated from Mongolian soda lakes, and phylotypes from amoA sequences were similar with yet uncultured beta-AOB from different biofilms. Sequences related to N. halophila were frequently found at all salinities. Neither gamma-AOB nor ammonia-oxidizing Archaea were recorded in these enrichment cultures.
authors.affiliation: Max Planck Institute for Evolutionary Biology, Plön, Germany. cdorado@ucn.cl
authors.forename: Cristina
authors.initials: C
authors.lastname: Dorador
authors.forename: Annika
authors.initials: A
authors.lastname: Busekow
authors.forename: Irma
authors.initials: I
authors.lastname: Vila
authors.forename: Johannes F
authors.initials: JF
authors.lastname: Imhoff
authors.forename: Karl-Paul
authors.initials: KP
authors.lastname: Witzel
mesh_terms: D000222:Adaptation, Physiological; D000531:Altitude; D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D002677:Chile; D004269:DNA, Bacterial / Q000032:analysis; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010802:Phylogeny; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D054712:Salinity; D012965:Sodium Chloride / Q000378:metabolism*; D053833:Wetlands
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D000641:Ammonia