scholarly journals Nitrification of archaeal ammonia oxidizers in a high- temperature hot spring

2016 ◽  
Vol 13 (7) ◽  
pp. 2051-2060 ◽  
Author(s):  
Shun Chen ◽  
Xiaotong Peng ◽  
Hengchao Xu ◽  
Kaiwen Ta
Keyword(s):  
High Temperature ◽  
16S Rrna ◽  
Bottom Sediments ◽  
Ammonia Oxidation ◽  
Hot Spring ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonia Oxidizers ◽  
Oxidation Rates

Abstract. The oxidation of ammonia by microbes has been shown to occur in diverse natural environments. However, the link of in situ nitrification activity to taxonomic identities of ammonia oxidizers in high-temperature environments remains poorly understood. Here, we studied in situ ammonia oxidation rates and the diversity of ammonia-oxidizing Archaea (AOA) in surface and bottom sediments at 77 °C in the Gongxiaoshe hot spring, Tengchong, Yunnan, China. The in situ ammonia oxidation rates measured by the 15N-NO3− pool dilution technique in the surface and bottom sediments were 4.80 and 5.30 nmol N g−1 h−1, respectively. Real-time quantitative polymerase chain reaction (qPCR) indicated that the archaeal 16S rRNA genes and amoA genes were present in the range of 0.128 to 1.96  ×  108 and 2.75 to 9.80  ×  105 gene copies g−1 sediment, respectively, while bacterial amoA was not detected. Phylogenetic analysis of 16S rRNA genes showed high sequence similarity to thermophilic Candidatus Nitrosocaldus yellowstonii, which represented the most abundant operational taxonomic units (OTU) in both surface and bottom sediments. The archaeal predominance was further supported by fluorescence in situ hybridization (FISH) visualization. The cell-specific rate of ammonia oxidation was estimated to range from 0.410 to 0.790 fmol N archaeal cell−1 h−1, higher than those in the two US Great Basin hot springs. These results suggest the importance of archaeal rather than bacterial ammonia oxidation in driving the nitrogen cycle in terrestrial geothermal environments.

scholarly journals Composition of ammonia-oxidizing archaea and their contribution to nitrification in a high-temperature hot spring

2015 ◽  
Vol 12 (19) ◽  
pp. 16255-16283
Author(s):  
S. Chen ◽  
X.-T. Peng ◽  
H.-C. Xu ◽  
K.-W. Ta
Keyword(s):  
High Temperature ◽  
16S Rrna ◽  
Bottom Sediments ◽  
Ammonia Oxidation ◽  
Hot Spring ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Oxidation Rates ◽  
Ammonia Oxidizing Archaea

Abstract. The oxidation of ammonia by microbes and associated organisms has been shown to occur in diverse natural environments. However, the contribution of ammonia-oxidizing archaea to nitrification in high-temperature environments remains unclear. Here, we studied in situ ammonia oxidation rates and the abundance of ammonia-oxidizing archaea (AOA) in surface and bottom sediments at 77 °C in the Gongxiaoshe hot spring, Tengchong, Yunnan, China. The in situ ammonia oxidation rates measured by the 15N–NO3- pool dilution technique in the surface sinter and bottom sediments were 4.8 and 5.3 nmol N g−1 h−1, respectively. Relative abundances of Crenarchaea in both samples were determined by fluorescence in situ hybridization (FISH). Phylogenetic analysis of 16S rRNA genes showed high sequence similarity to thermophilic "Candidatus Nitrosocaldus yellowstonii", which represented the most abundant operation taxonomic units (OTU) in both sediments. Furthermore, bacterial amoA was not detected in this study. Quantitative PCR (qPCR) indicated that AOA and 16S rRNA genes were present in the range of 2.75 to 9.80 × 105 and 0.128 to 1.96 × 108 gene copies g−1 sediment. The cell-specific nitrification rates were estimated to be in the range of 0.41 to 0.79 fmol N archaeal cell−1 h−1, which is consistent with earlier estimates in estuary environments. This study demonstrated that AOA were widely involved in nitrification in this hot spring. It further indicated the importance of archaea rather than bacteria in driving the nitrogen cycle in terrestrial geothermal environments.

scholarly journals Microbiological and Geochemical Heterogeneity in an In Situ Uranium Bioremediation Field Site

2005 ◽  
Vol 71 (10) ◽  
pp. 6308-6318 ◽  
Author(s):  
Helen A. Vrionis ◽  
Robert T. Anderson ◽  
Irene Ortiz-Bernad ◽  
Kathleen R. O'Neill ◽  
Charles T. Resch ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Acid Volatile Sulfide ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Geochemical Heterogeneity

ABSTRACT The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely spaced sampling intervals, horizontally and vertically, in both sediment and groundwater are necessary in order to obtain a more in-depth understanding of microbial processes and the relative contribution of attached and planktonic populations to in situ uranium bioremediation.

scholarly journals Responses of Active Ammonia Oxidizers and Nitrification Activity in Eutrophic Lake Sediments to Nitrogen and Temperature

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Ling Wu ◽  
Cheng Han ◽  
Guangwei Zhu ◽  
Wenhui Zhong
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonia Oxidizers ◽  
Nitrogen Input ◽  
Nitrification Activity ◽  
Ammonia Oxidizing Archaea ◽  
Nitrogen Inputs

ABSTRACTAmmonium concentrations and temperature drive the activities of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), but their effects on these microbes in eutrophic freshwater sediments are unclear. In this study, surface sediments collected from areas of Taihu Lake (China) with different degrees of eutrophication were incubated under three levels of nitrogen input and temperature, and the autotrophic growth of ammonia oxidizers was assessed using13C-labeled DNA-based stable-isotope probing (SIP), while communities were characterized using MiSeq sequencing and phylogenetic analysis of 16S rRNA genes. Nitrification rates in sediment microcosms were positively correlated with nitrogen inputs, but there was no marked association with temperature. Incubation of SIP microcosms indicated that AOA and AOBamoAgenes were labeled by13C at 20°C and 30°C in the slightly eutrophic sediment, and AOBamoAgenes were labeled to a much greater extent than AOAamoAgenes in the moderately eutrophic sediment after 56 days. Phylogenetic analysis of13C-labeled 16S rRNA genes revealed that the active AOA were mainly affiliated with theNitrosopumiluscluster, with theNitrososphaeracluster dominating in the slightly eutrophic sediment at 30°C with low ammonium input (1 mM). Active AOB communities were more sensitive to nitrogen input and temperature than were AOA communities, and they were exclusively dominated by theNitrosomonascluster, which tended to be associated withNitrosomonadaceae-like lineages.Nitrosomonassp. strain Is79A3 tended to dominate the moderately eutrophic sediment at 10°C with greater ammonium input (2.86 mM). The relative abundance responses of the major active communities to nitrogen input and temperature gradients varied, indicating niche differentiation and differences in the physiological metabolism of ammonia oxidizers that are yet to be described.IMPORTANCEBoth archaea and bacteria contribute to ammonia oxidation, which plays a central role in the global cycling of nitrogen and is important for reducing eutrophication in freshwater environments. The abundance and activities of ammonia-oxidizing archaea and bacteria in eutrophic limnic sediments vary with different ammonium concentrations or with seasonal shifts, and how the two factors affect nitrification activity, microbial roles, and active groups in different eutrophic sediments is unclear. The significance of our research is in identifying the archaeal and bacterial responses to anthropogenic activity and climate change, which will greatly enhance our understanding of the physiological metabolic differences of ammonia oxidizers.

scholarly journals Cultivation-Independent Examination of Horizontal Transfer and Host Range of an IncP-1 Plasmid among Gram-Positive and Gram-Negative Bacteria Indigenous to the Barley Rhizosphere

2006 ◽  
Vol 72 (10) ◽  
pp. 6687-6692 ◽  
Author(s):  
Sanin Musovic ◽  
Gunnar Oregaard ◽  
Niels Kroer ◽  
Søren J. Sørensen
Keyword(s):  
16S Rrna ◽  
Host Range ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Gram Positive ◽  
Gram Negative ◽  
Indigenous Bacteria ◽  
Transfer Frequency

ABSTRACTThe host range and transfer frequency of an IncP-1 plasmid (pKJK10) among indigenous bacteria in the barley rhizosphere was investigated. A new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16S rRNA gene classification was used. Indigenous transconjugant rhizosphere bacteria were collected by fluorescence-activated cell sorting and identified by cloning and sequencing of 16S rRNA genes from the sorted cells. The host range of the pKJK10 plasmid was exceptionally broad, as it included not only bacteria belonging to the alpha, beta, and gamma subclasses of theProteobacteria, but alsoArthrobactersp., a gram-positive member of theActinobacteria. The transfer frequency (transconjugants per donor) from thePseudomonas putidadonor to the indigenous bacteria was 7.03 × 10−2± 3.84 × 10−2. This is the first direct documentation of conjugal transfer between gram-negative donor and gram-positive recipient bacteria in situ.

Heterogeneity between 16S ribosomal RNA gene copies borne by one Desulfitobacterium strain is caused by different 100-200 bp insertions in the 5´ region

2007 ◽  
Vol 53 (1) ◽  
pp. 116-128 ◽  
Author(s):  
Richard Villemur ◽  
Philippe Constant ◽  
Annie Gauthier ◽  
Martine Shareck ◽  
Réjean Beaudet
Keyword(s):  
In Situ Hybridization ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Ribosomal Rna ◽  
16S Ribosomal Rna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Gene Copies

Strains of Desulfitobacterium hafniense, such as strains PCP-1, DP7, TCE1, and TCP-A, have unusual long 16S ribosomal RNA (rRNA) genes due to an insertion of approximately 100 bp in the 5' region. In this report, we analyzed the 16S rRNA genes of different Desulfitobacterium strains to determine if such an insertion is a common feature of desulfitobacteria. We amplified this region by polymerase chain reaction (PCR) from eight Desulfitobacterium strains (D. hafniense strains PCP-1, DP7, TCP-A, TCE1, and DCB-2; D. dehalogenans; D. chlororespirans; and Desulfitobacterium sp. PCE1) and resolved each PCR product by denaturing gradient gel electrophoresis (DGGE). All strains had from two to seven DGGE- migrating bands, suggesting heterogeneity in their 16S rRNA gene copies. For each strain, the 5' region of the 16S rRNA genes was amplified and a clone library was derived. Clones corresponding to most PCR–DGGE migration bands were isolated. Sequencing of representative clones revealed that the heterogeneity was generated by insertions of 100–200 bp. An insertion was found in at least one copy of the 16S rRNA gene in all examined strains. In total, we found eight different types of insertions (INS1–INS8) that varied from 123 to 193 nt in length. Two-dimensional structural analyses of transcribed sequences predicted that all insertions would form an energetically stable loop. Reverse transcriptase – PCR experiments revealed that most of the observed insertions in the Desulfitobacterium strains were excised from the mature 16S rRNA transcripts. Insertions were not commonly found in bacterial 16S rRNA genes, and having a different insertion in several 16S rRNA gene copies borne by a single bacterial species was rarely observed. The function of these insertions is not known, but their occurrence can have an important impact in deriving 16S rRNA oligonucleotidic fluorescence in situ hybridization probes, as these insertions can be excised from 16S rRNA transcripts.Key words: Desulfitobacterium, 16S ribosomal RNA genes, heterogeneity, gene insertions, fluorescence in situ hybridization.

scholarly journals Potential Interactions of Particle-Associated Anammox Bacteria with Bacterial and Archaeal Partners in the Namibian Upwelling System

2007 ◽  
Vol 73 (14) ◽  
pp. 4648-4657 ◽  
Author(s):  
Dagmar Woebken ◽  
Bernhard M. Fuchs ◽  
Marcel M. M. Kuypers ◽  
Rudolf Amann
Keyword(s):  
16S Rrna ◽  
Free Water ◽  
Water Phase ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Anammox Bacteria ◽  
Upwelling System ◽  
Group I ◽  
Anammox Activity

ABSTRACT Recent studies have shown that the anaerobic oxidation of ammonium by anammox bacteria plays an important role in catalyzing the loss of nitrogen from marine oxygen minimum zones (OMZ). However, in situ oxygen concentrations of up to 25 μM and ammonium concentrations close to or below the detection limit in the layer of anammox activity are hard to reconcile with the current knowledge of the physiology of anammox bacteria. We therefore investigated samples from the Namibian OMZ by comparative 16S rRNA gene analysis and fluorescence in situ hybridization. Our results showed that “Candidatus Scalindua” spp., the typical marine anammox bacteria, colonized microscopic particles that were likely the remains of either macroscopic marine snow particles or resuspended particles. These particles were slightly but significantly (P < 0.01) enriched in Gammaproteobacteria (11.8% ± 5.0%) compared to the free-water phase (8.1% ± 1.8%). No preference for the attachment to particles could be observed for members of the Alphaproteobacteria and Bacteroidetes, which were abundant (12 to 17%) in both habitats. The alphaproteobacterial SAR11 clade, the Euryarchaeota, and group I Crenarchaeota, were all significantly depleted in particles compared to their presence in the free-water phase (16.5% ± 3.5% versus 2.6% ± 1.7%, 2.7% ± 1.9% versus <1%, and 14.9% ± 4.6% versus 2.2% ± 1.8%, respectively, all P < 0.001). Sequence analysis of the crenarchaeotal 16S rRNA genes showed a 99% sequence identity to the nitrifying “Nitrosopumilus maritimus.” Even though we could not observe conspicuous consortium-like structures of anammox bacteria with particle-enriched bacterioplankton groups, we hypothesize that members of Gammaproteobacteria, Alphaproteobacteria, and Bacteroidetes play a critical role in extending the anammox reaction to nutrient-depleted suboxic water layers in the Namibian upwelling system by creating anoxic, nutrient-enriched microniches.

scholarly journals Bacteriohopanetetrol-<i>x</i>: constraining its application as a lipid biomarker for marine anammox using the water column oxygen gradient of the Benguela upwelling system

2022 ◽  
Vol 19 (1) ◽  
pp. 201-221
Author(s):  
Zoë R. van Kemenade ◽  
Laura Villanueva ◽  
Ellen C. Hopmans ◽  
Peter Kraal ◽  
Harry J. Witte ◽  
...  
Keyword(s):  
16S Rrna ◽  
Water Column ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonium Oxidation ◽  
Oxygen Gradient ◽  
Upwelling System ◽  
Benguela Upwelling ◽  
Ladderane Lipids

Abstract. Interpreting lipid biomarkers in the sediment archive requires a good understanding of their application and limitations in modern systems. Recently it was discovered that marine bacteria performing anaerobic ammonium oxidation (anammox), belonging to the genus Ca. Scalindua, uniquely synthesize a stereoisomer of bacteriohopanetetrol (“BHT-x”). The ratio of BHT-x over total bacteriohopanetetrol (BHT, ubiquitously synthesized by diverse bacteria) has been suggested as a proxy for water column anoxia. As BHT has been found in sediments over 50 Myr old, BHT-x has the potential to complement and extend the sedimentary biomarker record of marine anammox, conventionally constructed using ladderane lipids. Yet, little is known about the distribution of BHT-x in relation to the distribution of ladderanes and to the genetic evidence of Ca. Scalindua in modern marine systems. Here, we investigate the distribution of BHT-x and the application of the BHT-x ratio in relation to distributions of ladderane intact polar lipids (IPLs), ladderane fatty acids (FAs) and Ca. Scalindua 16S rRNA genes in suspended particulate matter (SPM) from the water column of the Benguela upwelling system (BUS), sampled across a large oxygen gradient. In BUS SPM, high BHT-x abundances were restricted to the oxygen-deficient zone on the continental shelf (at [O2] < 45 µmol L−1, in all but one case). High BHT-x abundances co-occurred with high abundances of the Ca. Scalindua 16S rRNA gene (relative to the total number of bacterial 16S rRNA genes) and ladderane IPLs. At shelf stations with [O2] > 50 µmol L−1, the BHT-x ratio was < 0.04 (in all but one case). In apparent contradiction, ladderane FAs and low abundances of BHT and BHT-x (resulting in BHT-x ratios > 0.04) were also detected in oxygenated offshore waters ([O2] up to 180 µmol L−1), whereas ladderane IPLs were undetected. The index of ladderane lipids with five cyclobutane rings (NL5) correlates with in situ temperature. NL5-derived temperatures suggested that ladderane FAs in the offshore waters were not synthesized in situ but were transported down-slope from warmer shelf waters. Thus, in sedimentary archives of systems with known lateral organic matter transport, such as the BUS, relative BHT and BHT-x abundances should be carefully considered. In such systems, a higher BHT-x ratio may act as a safer threshold for deoxygenation and/or Ca. Scalindua presence: our results and previous studies indicate that a BHT-x ratio of ≥ 0.2 is a robust threshold for oxygen-depleted waters ([O2] < 50 µmol kg−1). In our data, ratios of ≥ 0.2 coincided with Ca. Scalindua 16S rRNA genes in all samples (n=62), except one. Lastly, when investigating in situ anammox, we highlight the importance of using ladderane IPLs over BHT-x and/or ladderane FAs; these latter compounds are more recalcitrant and may derive from transported fossil anammox bacteria remnants.

scholarly journals In-depth analysis of Bacillus anthracis 16S rRNA genes and transcripts reveals intra- and intergenomic diversity and facilitates anthrax detection

2021 ◽  
Author(s):  
Peter Braun ◽  
Fee Zimmermann ◽  
Mathias C Walter ◽  
Sonja Mantel ◽  
Karin Aistleitner ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Species ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Close Relative ◽  
Rrna Gene ◽  
Copy Numbers ◽  
Depth Analysis

Analysis of 16S ribosomal RNA (rRNA) genes provides a central means of taxonomic classification of bacterial species. Based on presumed sequence identity among species of the Bacillus cereus sensu lato group, the 16S rRNA genes of B. anthracis have been considered unsuitable for diagnosis of the anthrax pathogen. With the recent identification of a single nucleotide polymorphism in some 16S rRNA gene copies, specific identification of B. anthracis becomes feasible. Here, we designed and evaluated a set of in situ-, in vitro- and in silico-assays to assess the yet unknown 16S-state of B. anthracis from different perspectives. Using a combination of digital PCR, fluorescence in situ hybridization, long-read genome sequencing and bioinformatics we were able to detect and quantify a unique 16S rRNA gene allele of B. anthracis (16S-BA-allele). This allele was found in all available B. anthracis genomes and may facilitate differentiation of the pathogen from any close relative. Bioinformatics analysis of 959 B. anthracis genome data-sets inferred that abundances and genomic arrangements of the 16S-BA-allele and the entire rRNA operon copy-numbers differ considerably between strains. Expression ratios of 16S-BA-alleles were proportional to the respective genomic allele copy-numbers. The findings and experimental tools presented here provide detailed insights into the intra- and intergenomic diversity of 16S rRNA genes and may pave the way for improved identification of B. anthracis and other pathogens with diverse rRNA operons.

scholarly journals Symbiosis and Insect Diversification: an Ancient Symbiont of Sap-Feeding Insects from the Bacterial Phylum Bacteroidetes

2005 ◽  
Vol 71 (12) ◽  
pp. 8802-8810 ◽  
Author(s):  
Nancy A. Moran ◽  
Phat Tran ◽  
Nicole M. Gerardo
Keyword(s):  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Symbionts ◽  
Large Group ◽  
Sap Feeding ◽  
In Situ Hybridizations

ABSTRACT Several insect groups have obligate, vertically transmitted bacterial symbionts that provision hosts with nutrients that are limiting in the diet. Some of these bacteria have been shown to descend from ancient infections. Here we show that the large group of related insects including cicadas, leafhoppers, treehoppers, spittlebugs, and planthoppers host a distinct clade of bacterial symbionts. This newly described symbiont lineage belongs to the phylum Bacteroidetes. Analyses of 16S rRNA genes indicate that the symbiont phylogeny is completely congruent with the phylogeny of insect hosts as currently known. These results support the ancient acquisition of a symbiont by a shared ancestor of these insects, dating the original infection to at least 260 million years ago. As visualized in a species of spittlebug (Cercopoidea) and in a species of sharpshooter (Cicadellinae), the symbionts have extraordinarily large cells with an elongate shape, often more than 30 μm in length; in situ hybridizations verify that these correspond to the phylum Bacteroidetes. “Candidatus Sulcia muelleri” is proposed as the name of the new symbiont.

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