scholarly journals Distribution and Diversity of Archaeal and Bacterial Ammonia Oxidizers in Salt Marsh Sediments

2009 ◽  
Vol 75 (23) ◽  
pp. 7461-7468 ◽  
Author(s):  
Nicole S. Moin ◽  
Katelyn A. Nelson ◽  
Alexander Bush ◽  
Anne E. Bernhard

ABSTRACT Diversity and abundance of ammonia-oxidizing Betaproteobacteria (β-AOB) and archaea (AOA) were investigated in a New England salt marsh at sites dominated by short or tall Spartina alterniflora (SAS and SAT sites, respectively) or Spartina patens (SP site). AOA amoA gene richness was higher than β-AOB amoA richness at SAT and SP, but AOA and β-AOB richness were similar at SAS. β-AOB amoA clone libraries were composed exclusively of Nitrosospira-like amoA genes. AOA amoA genes at SAT and SP were equally distributed between the water column/sediment and soil/sediment clades, while AOA amoA sequences at SAS were primarily affiliated with the water column/sediment clade. At all three site types, AOA were always more abundant than β-AOB based on quantitative PCR of amoA genes. At some sites, we detected 109 AOA amoA gene copies g of sediment−1. Ratios of AOA to β-AOB varied over 2 orders of magnitude among sites and sampling dates. Nevertheless, abundances of AOA and β-AOB amoA genes were highly correlated. Abundance of 16S rRNA genes affiliated with Nitrosopumilus maritimus, Crenarchaeota group I.1b, and pSL12 were positively correlated with AOA amoA abundance, but ratios of amoA to 16S rRNA genes varied among sites. We also observed a significant effect of pH on AOA abundance and a significant salinity effect on both AOA and β-ΑΟΒ abundance. Our results expand the distribution of AOA to salt marshes, and the high numbers of AOA at some sites suggest that salt marsh sediments serve as an important habitat for AOA.

2009 ◽  
Vol 75 (12) ◽  
pp. 4211-4215 ◽  
Author(s):  
Katelyn A. Nelson ◽  
Nicole S. Moin ◽  
Anne E. Bernhard

ABSTRACT Crenarchaeal 16S rRNA sequences constituted over 70% of the archaeal clones recovered from three salt marsh sites dominated by different grasses. Group I.1a Crenarchaeota dominated at two sites, while group I.3b Crenarchaeota sequences were most abundant at a third site. Abundances of 16S rRNA genes related to “Candidatus Nitrosopumilus maritimus” differed by site and sampling date.


2011 ◽  
Vol 77 (21) ◽  
pp. 7469-7478 ◽  
Author(s):  
Anyi Hu ◽  
Nianzhi Jiao ◽  
Rui Zhang ◽  
Zao Yang

ABSTRACTMarine group ICrenarchaeota(MGI) represents a ubiquitous and numerically predominant microbial population in marine environments. An understanding of the spatial dynamics of MGI and its controlling mechanisms is essential for an understanding of the role of MGI in energy and element cycling in the ocean. In the present study, we investigated the diversity and abundance of MGI in the East China Sea (ECS) by analysis of crenarchaeal 16S rRNA gene, the ammonia monooxygenase geneamoA, and the biotin carboxylase geneaccA. Quantitative PCR analyses revealed that these genes were higher in abundance in the mesopelagic than in the euphotic zone. In addition, the crenarchaealamoAgene was positively correlated with the copy number of the MGI 16S rRNA gene, suggesting that most of the MGI in the ECS are nitrifiers. Furthermore, the ratios of crenarchaealaccAtoamoAor to MGI 16S rRNA genes increased from the euphotic to the mesopelagic zone, suggesting that the role of MGI in carbon cycling may change from the epipelagic to the mesopelagic zones. Denaturing gradient gel electrophoretic profiling of the 16S rRNA genes revealed depth partitioning in MGI community structures. Clone libraries of the crenarchaealamoAandaccAgenes showed both “shallow” and “deep” groups, and their relative abundances varied in the water column. Ecotype simulation analysis revealed that MGI in the upper ocean could diverge into special ecotypes associated with depth to adapt to the light gradient across the water column. Overall, our results showed niche partitioning of the MGI population and suggested a shift in their ecological functions between the euphotic and mesopelagic zones of the ECS.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
A. E. Bernhard ◽  
J. Beltz ◽  
A. E. Giblin ◽  
B. J. Roberts

AbstractFew studies have focused on broad scale biogeographic patterns of ammonia oxidizers in coastal systems, yet understanding the processes that govern them is paramount to understanding the mechanisms that drive biodiversity, and ultimately impact ecosystem processes. Here we present a meta-analysis of 16 years of data of ammonia oxidizer abundance, diversity, and activity in New England (NE) salt marshes and 5 years of data from marshes in the Gulf of Mexico (GoM). Potential nitrification rates were more than 80x higher in GoM compared to NE marshes. However, nitrifier abundances varied between regions, with ammonia-oxidizing archaea (AOA) and comammox bacteria significantly greater in GoM, while ammonia-oxidizing bacteria (AOB) were more than 20x higher in NE than GoM. Total bacterial 16S rRNA genes were also significantly greater in GoM marshes. Correlation analyses of rates and abundance suggest that AOA and comammox are more important in GoM marshes, whereas AOB are more important in NE marshes. Furthermore, ratios of nitrifiers to total bacteria in NE were as much as 80x higher than in the GoM, suggesting differences in the relative importance of nitrifiers between these systems. Communities of AOA and AOB were also significantly different between the two regions, based on amoA sequences and DNA fingerprints (terminal restriction fragment length polymorphism). Differences in rates and abundances may be due to differences in salinity, temperature, and N loading between the regions, and suggest significantly different N cycling dynamics in GoM and NE marshes that are likely driven by strong environmental differences between the regions.


2007 ◽  
Vol 73 (14) ◽  
pp. 4648-4657 ◽  
Author(s):  
Dagmar Woebken ◽  
Bernhard M. Fuchs ◽  
Marcel M. M. Kuypers ◽  
Rudolf Amann

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Claudia Maturana-Martínez ◽  
Camila Fernández ◽  
Humberto E. González ◽  
Pierre E. Galand

Microorganisms play a crucial role in biogeochemical processes affecting the primary production and biogeochemical cycles of the ocean. In subpolar areas, the increment of the water temperature induced by climate change could lead to changes in the structure and activity of planktonic microbial communities. To understand how the structure of the microbial community in Chilean Patagonian fjords could be affected by climate change, we analyzed the composition of the prokaryotic community (bacteria-archaea) in two fjords (Pia and Yendegaia) with contrasting morphological and hydrological features. We targeted both the standing stock (16S rRNA genes) and the active fraction (16S rRNA transcripts) of the microbial communities during two consecutive austral winters. Our results showed that in both fjords, the active community had higher diversity and stronger biogeographic patterns when compared to the standing stock. Members of the Alpha-, Gamma-, and Deltaproteobacteria followed by archaea from the Marine Group I (Thaumarchaeota) dominated the active communities in both fjords. However, in Pia fjord, which has a marine-terminating glacier, the composition of the microbial community was directly influenced by the freshwater discharges from the adjacent glacier, and indirectly by a possible upwelling phenomenon that could bring deep sea bacteria such as SAR202 to the surface layer. In turn, in the Yendegaia, which has a land-terminating glacier, microbial communities were more similar to the ones described in oceanic waters. Furthermore, in Yendegaia fjord, inter-annual differences in the taxonomic composition and diversity of the microbial community were observed. In conclusion, Yendegaia fjord, without glacier calving, represents a fjord type that will likely be more common under future climate scenarios. Our results showing distinct Yendegaia communities, with for example more potential nitrogen-fixing microorganisms (Planctomycetes), indicate that as a result of climate change, changing planktonic communities could potentially impact biogeochemical processes and nutrient sources in subantarctic fjords.


2022 ◽  
Vol 19 (1) ◽  
pp. 201-221
Author(s):  
Zoë R. van Kemenade ◽  
Laura Villanueva ◽  
Ellen C. Hopmans ◽  
Peter Kraal ◽  
Harry J. Witte ◽  
...  

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.


2000 ◽  
Vol 66 (7) ◽  
pp. 3037-3043 ◽  
Author(s):  
Marc E. Frischer ◽  
Jean M. Danforth ◽  
Michele A. Newton Healy ◽  
F. Michael Saunders

ABSTRACT rRNA-targeted oligonucleotide probes have become powerful tools for describing microbial communities, but their use in sediments remains difficult. Here we describe a simple technique involving homogenization, detergents, and dispersants that allows the quantitative extraction of cells from formalin-preserved salt marsh sediments. Resulting cell extracts are amenable to membrane blotting and hybridization protocols. Using this procedure, the efficiency of cell extraction was high (95.7% � 3.7% [mean � standard deviation]) relative to direct DAPI (4′,6′-diamidino-2-phenylindole) epifluorescence cell counts for a variety of salt marsh sediments. To test the hypothesis that cells were extracted without phylogenetic bias, the relative abundance (depth distribution) of five major divisions of the gram-negative mesophilic sulfate-reducing delta proteobacteria were determined in sediments maintained in a tidal mesocosm system. A suite of six 16S rRNA-targeted oligonucleotide probes were utilized. The apparent structure of sulfate-reducing bacteria communities determined from whole-cell and RNA extracts were consistent with each other (r 2 = 0.60), indicating that the whole-cell extraction and RNA extraction hybridization approaches for describing sediment microbial communities are equally robust. However, the variability associated with both methods was high and appeared to be a result of the natural heterogeneity of sediment microbial communities and methodological artifacts. The relative distribution of sulfate-reducing bacteria was similar to that observed in natural marsh systems, providing preliminary evidence that the mesocosm systems accurately simulate native marsh systems.


2009 ◽  
Vol 4 (4) ◽  
pp. 558-566 ◽  
Author(s):  
Alexandra Demiri ◽  
Alexandra Meziti ◽  
Sokratis Papaspyrou ◽  
Maria Thessalou-Legaki ◽  
Konstantinos Kormas

AbstractWe investigated the diversity of the bacterial 16S rRNA genes occurring on the abdominal setal tufts and in the emptied midgut of the marine mudshrimp Pestarella tyrrhena (Decapoda: Thalassinidea). There were no dominant phylotypes on the setal tufts. The majority of the phylotypes belonged to the phylum Bacteroidetes, frequently occurring in the water column. The rest of the phylotypes were related to anoxygenic photosynthetic α-Proteobacteria and to Actinobacteria. This bacterial profile seems more of a marine assemblage rather than a specific one suggesting that no specific microbial process can be inferred on the setal tufts. In the emptied midgut, 64 clones were attributed to 16 unique phylotypes with the majority (40.6%) belonging to the γ-Proteobacteria, specifically to the genus Vibrio, a marine group with known symbionts of decapods. The next most abundant group was the ɛ-Proteobacteria (28.1%), with members as likely symbionts related to the processes involving redox reactions occurring in the midgut. In addition, phylotypes related to the Spirochaetes (10.9%) were also present, with relatives capable of symbiosis conducting a nitrite associated metabolism. Entomoplasmatales, Bacteroidetes and Actinobacteria related phylotypes were also found. These results indicate a specific bacterial community dominated by putative symbiotic Bacteria within the P. tyrrhena’s midgut.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8074
Author(s):  
Richard McKinney ◽  
Alana Hanson ◽  
Roxanne Johnson ◽  
Michael Charpentier

Measurement of the apparent conductivity of salt marsh sediments using electromagnetic induction (EMI) is a rapid alternative to traditional methods of salinity determination that can be used to map soil salinity across a marsh surface. Soil salinity measures can provide information about marsh processes, since salinity is important in determining the structure and function of tidally influenced marsh communities. While EMI has been shown to accurately reflect salinity to a specified depth, more information is needed on the potential for spatial and temporal variability in apparent conductivity measures that may impact the interpretation of salinity data. In this study we mapped soil salinity at two salt marshes in the Narragansett Bay, RI estuary monthly over the course of several years to examine spatial and temporal trends in marsh salinity. Mean monthly calculated salinity was 25.8 ± 5.5 ppt at Narrow River marsh (NAR), located near the mouth of the Bay, and 17.7 ± 5.3 ppt at Passeonkquis marsh (PAS) located in the upper Bay. Salinity varied seasonally with both marshes, showing the lowest values (16.3 and 8.3 ppt, respectively) in April and highest values (35.4 and 26.2 ppt, respectively) in August. Contour plots of calculated salinities showed that while the mean whole-marsh calculated salinity at both sites changed over time, within-marsh patterns of higher versus lower salinity were maintained at NAR but changed over time at PAS. Calculated salinity was significantly negatively correlated with elevation at NAR during a sub-set of 12 sample events, but not at PAS. Best-supported linear regression models for both sites included one-month and 6-month cumulative rainfall, and tide state as potential factors driving observed changes in calculated salinity. Mapping apparent conductivity of salt marsh sediments may be useful both identifying within-marsh micro-habitats, and documenting marsh-wide changes in salinity over time.


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