scholarly journals Relationship of Temporal and Spatial Variabilities of Ammonia-Oxidizing Bacteria to Nitrification Rates in Monterey Bay, California

2005 ◽  
Vol 71 (2) ◽  
pp. 697-705 ◽  
Author(s):  
G. D. O'Mullan ◽  
B. B. Ward
Keyword(s):  
16S Rrna ◽  
Spatial Dynamics ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Ammonia Oxidizing Bacteria ◽  
Monterey Bay ◽  
Strong Positive Correlation ◽  
Clone Libraries ◽  
Bacterial Populations ◽  
Temporal And Spatial

ABSTRACT Temporal and spatial dynamics of ammonia-oxidizing bacteria (AOB) were examined using genes encoding 16S rRNA and ammonia monooxygenase subunit A (AmoA) in Monterey Bay, Calif. Samples were collected from three depths in the water column on four dates at one mid-bay station. Diversity estimators for the two genes showed a strong positive correlation, indicating that overlapping bacterial populations had been sampled by both sets of clone libraries. Some samples that were separated by only 15 m in depth had less genetic similarity than samples that were collected from the same depth months apart. Clone libraries from the Monterey Bay AOB community were dominated by Nitrosospira-like sequences and clearly differentiated from the adjacent AOB community in Elkhorn Slough. Many Monterey Bay clones clustered with previously identified 16S rRNA and amoA groups composed entirely of marine sequences, supporting the hypothesis that these groups are specific to the marine environment and are dominant marine AOB. In addition, novel, phylogenetically distinct groups of AOB sequences were identified and compared to sequences in the database. Only one cluster of gammaproteobacterial AOB was detected using 16S rRNA genes. Although significant genetic variation was detected in AOB populations from both vertical and temporal samples, no significant correlation was detected between diversity and environmental variables or the rate of nitrification.

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 Quantitative Assessment of Ammonia-Oxidizing Bacterial Communities in the Epiphyton of Submerged Macrophytes in Shallow Lakes

2010 ◽  
Vol 76 (6) ◽  
pp. 1813-1821 ◽  
Author(s):  
M. Coci ◽  
G. W. Nicol ◽  
G. N. Pilloni ◽  
M. Schmid ◽  
M. P. Kamst-van Agterveld ◽  
...  
Keyword(s):  
16S Rrna ◽  
Shallow Lakes ◽  
Submerged Macrophytes ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gene Copy ◽  
Potamogeton Pectinatus ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Potential Nitrification

ABSTRACT In addition to the benthic and pelagic habitats, the epiphytic compartment of submerged macrophytes in shallow freshwater lakes offers a niche to bacterial ammonia-oxidizing communities. However, the diversity, numbers, and activity of epiphytic ammonia-oxidizing bacteria have long been overlooked. In the present study, we analyzed quantitatively the epiphytic communities of three shallow lakes by a potential nitrification assay and by quantitative PCR of 16S rRNA genes. On the basis of the m2 of the lake surface, the gene copy numbers of epiphytic ammonia oxidizers were not significantly different from those in the benthic and pelagic compartments. The potential ammonia-oxidizing activities measured in the epiphytic compartment were also not significantly different from the activities determined in the benthic compartment. No potential ammonia-oxidizing activities were observed in the pelagic compartment. No activity was detected in the epiphyton of Chara aspera, the dominant submerged macrophyte in Lake Nuldernauw in The Netherlands. The presence of ammonia-oxidizing bacterial cells in the epiphyton of Potamogeton pectinatus was also demonstrated by fluorescent in situ hybridization microscopy images. By comparing the community composition as assessed by the 16S rRNA gene PCR-denaturing gradient gel electrophoresis approach, it was concluded that the epiphytic ammonia-oxidizing communities consisted of cells that were also present in the benthic and pelagic compartments. Of the environmental parameters examined, only the water retention time, the Kjeldahl nitrogen content, and the total phosphorus content correlated with potential ammonia-oxidizing activities. None of these parameters correlated with the numbers of gene copies related to ammonia-oxidizing betaproteobacteria.

scholarly journals Active Ammonia Oxidizers in an Acidic Soil Are Phylogenetically Closely Related to Neutrophilic Archaeon

2013 ◽  
Vol 80 (5) ◽  
pp. 1684-1691 ◽  
Author(s):  
Baozhan Wang ◽  
Yan Zheng ◽  
Rong Huang ◽  
Xue Zhou ◽  
Dongmei Wang ◽  
...  
Keyword(s):  
16S Rrna ◽  
Buoyant Density ◽  
Stable Isotope Probing ◽  
Acidic Soil ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Molecular Evidence ◽  
Ammonia Oxidizing Bacteria ◽  
Content Type ◽  
Metabolic Versatility

ABSTRACTAll cultivated ammonia-oxidizing archaea (AOA) within theNitrososphaeracluster (former soil group 1.1b) are neutrophilic. Molecular surveys also indicate the existence ofNitrososphaera-like phylotypes in acidic soil, but their ecological roles are poorly understood. In this study, we present molecular evidence for the chemolithoautotrophic growth ofNitrososphaera-like AOA in an acidic soil with pH 4.92 using DNA-based stable isotope probing (SIP). Soil microcosm incubations demonstrated that nitrification was stimulated by urea fertilization and accompanied by a significant increase in the abundance of AOA rather than ammonia-oxidizing bacteria (AOB). Real-time PCR analysis ofamoAgenes as a function of the buoyant density of the DNA gradient following the ultracentrifugation of the total DNA extracted from SIP microcosms indicated a substantial growth of soil AOA during nitrification. Pyrosequencing of the total 16S rRNA genes in the “heavy” DNA fractions suggested that archaeal communities were labeled to a much greater extent than soil AOB. Acetylene inhibition further showed that13CO2assimilation by nitrifying communities depended solely on ammonia oxidation activity, suggesting a chemolithoautotrophic lifestyle. Phylogenetic analysis of both13C-labeledamoAand 16S rRNA genes revealed that most of the active AOA were phylogenetically closely related to the neutrophilic strainsNitrososphaera viennensisEN76 and JG1 within theNitrososphaeracluster. Our results provide strong evidence for the adaptive growth ofNitrososphaera-like AOA in acidic soil, suggesting a greater metabolic versatility of soil AOA than previously appreciated.

scholarly journals Phylogenetic Comparison of the Methanogenic Communities from an Acidic, Oligotrophic Fen and an Anaerobic Digester Treating Municipal Wastewater Sludge

2008 ◽  
Vol 74 (21) ◽  
pp. 6663-6671 ◽  
Author(s):  
Lisa M. Steinberg ◽  
John M. Regan
Keyword(s):  
16S Rrna ◽  
Municipal Wastewater ◽  
Anaerobic Digester ◽  
Wastewater Sludge ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Large Temperature ◽  
Clone Libraries ◽  
Average Sequence ◽  
Sequence Similarities

ABSTRACT Methanogens play a critical role in the decomposition of organics under anaerobic conditions. The methanogenic consortia in saturated wetland soils are often subjected to large temperature fluctuations and acidic conditions, imposing a selective pressure for psychro- and acidotolerant community members; however, methanogenic communities in engineered digesters are frequently maintained within a narrow range of mesophilic and circumneutral conditions to retain system stability. To investigate the hypothesis that these two disparate environments have distinct methanogenic communities, the methanogens in an oligotrophic acidic fen and a mesophilic anaerobic digester treating municipal wastewater sludge were characterized by creating clone libraries for the 16S rRNA and methyl coenzyme M reductase alpha subunit (mcrA) genes. A quantitative framework was developed to assess the differences between these two communities by calculating the average sequence similarity for 16S rRNA genes and mcrA within a genus and family using sequences of isolated and characterized methanogens within the approved methanogen taxonomy. The average sequence similarities for 16S rRNA genes within a genus and family were 96.0 and 93.5%, respectively, and the average sequence similarities for mcrA within a genus and family were 88.9 and 79%, respectively. The clone libraries of the bog and digester environments showed no overlap at the species level and almost no overlap at the family level. Both libraries were dominated by clones related to uncultured methanogen groups within the Methanomicrobiales, although members of the Methanosarcinales and Methanobacteriales were also found in both libraries. Diversity indices for the 16S rRNA gene library of the bog and both mcrA libraries were similar, but these indices indicated much lower diversity in the 16S digester library than in the other three libraries.

Phylogenetic Differentiation of Two Closely RelatedNitrosomonas spp. That Inhabit Different Sediment Environments in an Oligotrophic Freshwater Lake

1999 ◽  
Vol 65 (11) ◽  
pp. 4855-4862 ◽  
Author(s):  
Corinne B. Whitby ◽  
Jon R. Saunders ◽  
Juana Rodriguez ◽  
Roger W. Pickup ◽  
Alan McCarthy
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Freshwater Lake ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Relative Distribution ◽  
Sediment Samples ◽  
Oligonucleotide Hybridization

ABSTRACT The population of ammonia-oxidizing bacteria in a temperate oligotrophic freshwater lake was analyzed by recovering 16S ribosomal DNA (rDNA) from lakewater and sediment samples taken throughout a seasonal cycle. Nitrosospira and Nitrosomonas16S rRNA genes were amplified in a nested PCR, and the identity of the products was confirmed by oligonucleotide hybridization.Nitrosospira DNA was readily identified in all samples, and nitrosomonad DNA of the Nitrosomonas europaea-Nitrosomonas eutropha lineage was also directly detected, but during the summer months only. Phylogenetic delineation with partial (345 bp) 16S rRNA gene sequences of clones obtained from sediments confirmed the fidelity of the amplified nitrosomonad DNA and identified two sequence clusters closely related to either N. europaea or N. eutropha that were equated with the littoral and profundal sediment sites, respectively. Determination of 701-bp sequences for 16S rDNA clones representing each cluster confirmed this delineation. A PCR-restriction fragment length polymorphism (RFLP) system was developed that enabled identification of clones containing N. europaea and N. eutropha 16S rDNA sequences, including subclasses therein. It proved possible to analyze 16S rDNA amplified directly from sediment samples to determine the relative abundance of each species compared with that of the other. N. europaea and N. eutropha are very closely related, and direct evidence for their presence in lake systems is limited. The correlation of each species with a distinct spatial location in sediment is an unusual example of niche adaptation by two genotypically similar bacteria. Their occurrence and relative distribution can now be routinely monitored in relation to environmental variation by the application of PCR-RFLP analysis.

scholarly journals Intestinal TM7 bacterial phylogenies in active inflammatory bowel disease

2008 ◽  
Vol 57 (12) ◽  
pp. 1569-1576 ◽  
Author(s):  
Tanja Kuehbacher ◽  
Ateequr Rehman ◽  
Patricia Lepage ◽  
Stephan Hellmig ◽  
Ulrich R. Fölsch ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
16S Rrna ◽  
Molecular Techniques ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Base Substitution ◽  
Clone Libraries ◽  
Bowel Diseases ◽  
Inflammatory Bowel ◽  
Almost All

TM7 is a recently described subgroup of Gram-positive uncultivable bacteria originally found in natural environmental habitats. An association of the TM7 bacterial division with the inflammatory pathogenesis of periodontitis has been previously shown. This study investigated TM7 phylogenies in patients with inflammatory bowel diseases (IBDs). The mucosal microbiota of patients with active Crohn's disease (CD; n=42) and ulcerative colitis (UC; n=31) was compared with that of controls (n=33). TM7 consortia were examined using molecular techniques based on 16S rRNA genes, including clone libraries, sequencing and in situ hybridization. TM7 molecular signatures could be cloned from mucosal samples of both IBD patients and controls, but the composition of the clone libraries differed significantly. Taxonomic analysis of the sequences revealed a higher diversity of TM7 phylotypes in CD (23 different phylotypes) than in UC (10) and non-IBD controls (12). All clone libraries showed a high number of novel sequences (21 for controls, 34 for CD and 29 for UC). A highly atypical base substitution for bacterial 16S rRNA genes associated with antibiotic resistance was detected in almost all sequences from CD (97.3 %) and UC (100 %) patients compared to only 65.1 % in the controls. TM7 bacteria might play an important role in IBD similar to that previously described in oral inflammation. The alterations of TM7 bacteria and the genetically determined antibiotic resistance of TM7 species in IBD could be a relevant part of a more general alteration of bacterial microbiota in IBD as recently found, e.g. as a promoter of inflammation at early stages of disease.

scholarly journals Assessment of Microbial Diversity in Four Southwestern United States Soils by 16S rRNA Gene Terminal Restriction Fragment Analysis

2000 ◽  
Vol 66 (7) ◽  
pp. 2943-2950 ◽  
Author(s):  
John Dunbar ◽  
Lawrence O. Ticknor ◽  
Cheryl R. Kuske
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rdna ◽  
Restriction Fragment ◽  
Community Diversity ◽  
Detection Sensitivity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Clone Libraries

ABSTRACT The ability of terminal restriction fragment (T-RFLP or TRF) profiles of 16S rRNA genes to provide useful information about the relative diversity of complex microbial communities was investigated by comparison with other methods. Four soil communities representing two pinyon rhizosphere and two between-tree (interspace) soil environments were compared by analysis of 16S rRNA gene clone libraries and culture collections (Dunbar et al., Appl. Environ. Microbiol. 65:1662–1669, 1998) and by analysis of 16S rDNA TRF profiles of community DNA. The TRF method was able to differentiate the four communities in a manner consistent with previous comparisons of the communities by analysis of 16S rDNA clone libraries. TRF profiles were not useful for calculating and comparing traditional community richness or evenness values among the four soil environments. Statistics calculated from RsaI, HhaI, HaeIII, and MspI profiles of each community were inconsistent, and the combined data were not significantly different between samples. The detection sensitivity of the method was tested. In standard PCRs, a seeded population comprising 0.1 to 1% of the total community could be detected. The combined results demonstrate that TRF analysis is an excellent method for rapidly comparing the relationships between bacterial communities in environmental samples. However, for highly complex communities, the method appears unable to provide classical measures of relative community diversity.

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