Diel nitrogen fixation pattern of Trichodesmium: the interactive control of light and Ni

Rodriguez, Irene B.; Ho, Tung‐Yuan

doi:10.1038/srep04445

Cited by 44 publications

(27 citation statements)

References 31 publications

(63 reference statements)

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“…Among the cyanobacteria, nifH sequences assigned to Rivularia followed by Mastigocoleus , Cyanothece , Trichodesmium , and Anabaena were relatively higher as compared to other nifH harboring Cyanobacteria ( see Supporting Information text). Some heterocystous (e.g., Nostoc, Rivularia , and Calothrix , Jones ) and non‐heterocystous N 2 fixing cyanobacteria (e.g., Trichodesmium , Rodriguez and Ho and Lyngbia , Jones ) have known maximum N 2 ‐fixing activities during the day. These cyanobacteria which are known to have maximum N 2 ‐fixing activities during the day, have all been found associated with P. oceanica leaves (Supporting Information Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Nitrogen (N) demand of P. oceanica meadow and the percentage of possible contribution of N from N 2 fixation in undisturbed P. oceanica patches and unvegetated sediments in the study sites in the various sampling periods.Trichodesmium, and Anabaena were relatively higher as compared to other nifH harboring Cyanobacteria (see Supporting Information text). Some heterocystous (e.g., Nostoc, Rivularia, and Calothrix, Jones 1992) and non-heterocystous N 2 fixing cyanobacteria (e.g., Trichodesmium,Rodriguez and Ho 2014 …”

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confidence: 99%

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Temporal and spatial variability of in situ nitrogen fixation activities associated with the Mediterranean seagrass Posidonia oceanica meadows

Agawin

Ferriol

Sintes

et al. 2017

Limnology & Oceanography

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This study provides the first extensive data on in situ rates of N2 fixation in minimally disturbed Posidonia oceanica meadows and their temporal and spatial variability along the Mallorcan coasts in the Mediterranean Sea. Benthic bell‐jar chambers were deployed underwater enclosing (1) natural P. oceanica shoots, (2) matted sediment of P. oceanica with the leaves carefully removed by clipping to assess the contribution of N2 fixation associated with leaves, and (3) adjacent unvegetated sediment to assess the contribution of N2 fixation by the sediment. In all of the chambers, N2 fixation varied seasonally, with highest rates during summer and lowest in winter. Average N2 fixation rates in chambers enclosing natural P. oceanica shoots ranged from 0.06 mg N m−2 d−1 to 1.51 mg N m−2 d−1 (0.004–0.107 mmol N m−2 d−1) in summer. Careful removal of leaves generally reduced N2 fixation rates by 16–89%. The N2 fixation rates in unvegetated sediments ranging from 0.01 mg N m−2 d−1 to 1.99 to mg N m−2 d−1 (7.1 × 10−4–0.14 mmol N m−2 d−1) have similar magnitudes in sediments with P. oceanica. This suggests that these sediments are “hot spots” for N2 fixation. Exploratory analyses of environmental factors that may influence N2 fixation rates highlight temperature and pore water total phosphorus concentrations as important factors.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Temporal and spatial variability of in situ nitrogen fixation activities associated with the Mediterranean seagrass Posidonia oceanica meadows

Agawin

Ferriol

Sintes

et al. 2017

Limnology & Oceanography

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“…Given the elevated concentrations of Mn in the subtropical gyres (notably the NASTG) (Van Hulten et al, 2017), a Mn based SOD would be a likely candidate to replace Ni-SOD in Trichodesmium as the genome contains the gene coding for Mn-SOD as well (Dupont et al, 2008). Based on the current observations of lowest Ni concentrations in regions of known elevated nitrogen fixation, but most notably given observations elsewhere that nitrogen fixation can be stimulated by Ni additions (Ho, 2013;Ho et al, 2013;Rodriguez and Ho, 2014), it would appear Ni-SOD is the preferred SOD for nitrogen fixers in the Atlantic. However, other phototrophic organisms that are abundant in the Atlantic subtropical gyres such as the cyanobacteria Prochlorococcus and Synechococcous (Flombaum et al, 2013) also use Ni-SOD (Priya et al, 2007) and thus the role of Ni-SOD in explaining the Ni depletion pattern in the Atlantic remains speculative.…”

Section: Surface Distributionmentioning

confidence: 93%

“…It is conceivable that the lower surface concentrations of Ni in the NASTG compared to the SASTG are related to nitrogen fixation as nitrogen fixing microbes such as Trichodesmium are thought to have a relatively high Ni requirement (Nuester et al, 2012;Ho, 2013;Ho et al, 2013;Rodriguez and Ho, 2014) and estimates of nitrogen fixation are higher for the NA compared to the SA (Benavides and Voss, 2015). Our data in the West-Atlantic is consistent with this notion and the hypothesis of Schlosser et al (2014) who postulated that wet dust deposition in the Intertropical Convergence Zone (ITCZ) delivers Fe to the subtropical NA and this Fe stimulates nitrogen fixation.…”

Section: Surface Distributionmentioning

confidence: 99%

The Distribution of Nickel in the West-Atlantic Ocean, Its Relationship With Phosphate and a Comparison to Cadmium and Zinc

et al. 2020

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Nickel (Ni) is a bio-essential element required for the growth of phytoplankton. It is the least studied bio-essential element, mainly because surface ocean Ni concentrations are never fully depleted and Ni is not generally considered to be a limiting factor. However, stimulation of growth after Ni addition has been observed in past experiments when seemingly ample ambient dissolved Ni was present, suggesting not all dissolved Ni is bio-available. This study details the distribution of Ni along the GEOTRACES GA02 Atlantic Meridional section. Concentrations of Ni were lowest in the surface ocean and the lowest observed concentration of 1.7 nmol kg −1 was found in the northern hemisphere (NH). The generally lower surface concentrations in the NH subtropical gyre compared to the southern hemisphere (SH), might be related to a greater Ni uptake by nitrogen fixers that are stimulated by iron (Fe) deposition. The distribution of Ni resembles the distribution of cadmium (Cd) and also features a so called kink (change in the steepness of slope) in the Ni-PO 4 relationship. Like for Cd, this is caused by the mixing of Nordic and Antarctic origin water masses. The overall distribution of Ni is driven by mixing with an influence of regional remineralization. This influence of remineralization is, with a maximum remineralization contribution of 13% of the highest observed concentration, smaller than for Cd (30%), but larger than for zinc (Zn; 6%). The uptake pattern in the formation regions of Antarctic origin water masses is suggested to be more similar to Zn than to Cd, however, the surface concentrations of Ni are never fully depleted. This results in a North Atlantic concentration distribution of Ni where the trends of increasing and decreasing concentrations between water masses are similar to those observed for Cd, but the actual concentrations as well as the uptake and remineralization patterns are different between these elements.

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“…The significantly higher (p = 0.02) N 2 -fix rates measured in the SD treatment (Rahav et al, 2016b) may be related to a relatively larger release of Fe in this treatment and its relatively lower nitrate/phosphate ratio (∼10:1). In addition, the significantly (p < 0.05) higher Ni concentrations in SD as compared to A or C, is known to play an important role in the cellular physiology of diazotrophic cyanobacteria such as Trichodesmium (Rodriguez and Ho, 2014) and supports the latter observation and the appearance of this N 2 -fixer in the SD treatment (Rahav et al, 2016b). Both types of dry aerosol additions (SD and A) triggered a positive change (25-600% per 1 mg/L addition) in all rate and state measurements (Figures 5, 6), showing a general sequence (p < 0.05) of higher relative change in the rate parameters: N 2 -fix > BP > PP > Chla ≈ BA ≈ Syn for SD and BP > PP ≈ N 2 -fix > Chla ≈ BA ≈ Syn for A.…”

Section: Discussionmentioning

confidence: 99%

The Potential Impact of Saharan Dust and Polluted Aerosols on Microbial Populations in the East Mediterranean Sea, an Overview of a Mesocosm Experimental Approach

et al. 2016

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Recent estimates of nutrient budgets for the Eastern Mediterranean Sea (EMS) indicate that atmospheric aerosols play a significant role as suppliers of macro-and micro-nutrients to its Low Nutrient Low Chlorophyll water. Here we present the first mesocosm experimental study that examines the overall response of the oligotrophic EMS surface mixed layer (Cretan Sea, May 2012) to two different types of natural aerosol additions, "pure" Saharan dust (SD, 1.6 mg l −1 ) and mixed aerosols (A-polluted and desert origin, 1 mg l −1 ). We describe the rationale, the experimental set-up, the chemical characteristics of the ambient water and aerosols and the relative maximal biological impacts that resulted from the added aerosols. The two treatments, run in triplicates (3 m 3 each), were compared to control-unamended runs. Leaching of ∼2.1-2.8 and 2.2-3.7 nmol PO 4 and 20-26 and 53-55 nmol NO x was measured per each milligram of SD and A, respectively, representing an addition of ∼30% of the ambient phosphate concentrations. The nitrate/phosphate ratios added in the A treatment were twice than those added in the SD treatment. Both types of dry aerosols triggered a positive change (25-600% normalized per 1 mg l −1 addition) in most of the rate and state variables that were measured: bacterial abundance (BA), bacterial production (BP), Synechococcus (Syn) abundance, chlorophyll-a (chl-a), primary production (PP), and dinitrogen fixation (N 2 -fix), with relative changes among them following the sequence BP>PP≈N2-fix>chl-a≈BA≈Syn. Our results show that the "polluted" aerosols triggered a relatively larger biological Herut et al.Impact of Aerosols on LNLC Seawater change compared to the SD amendments (per a similar amount of mass addition), especially regarding BP and PP. We speculate that despite the co-limitation of P and N in the EMS, the additional N released by the A treatment may have triggered the relatively larger response in most of the rate and state variables as compared to SD. An implication of our study is that a warmer atmosphere in the future may increase dust emissions and influence the intensity and length of the already well stratified water column in the EMS and hence the impact of the aerosols as a significant external source of new nutrients.

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Diel nitrogen fixation pattern of Trichodesmium: the interactive control of light and Ni

Cited by 44 publications

References 31 publications

Temporal and spatial variability of in situ nitrogen fixation activities associated with the Mediterranean seagrass Posidonia oceanica meadows

Temporal and spatial variability of in situ nitrogen fixation activities associated with the Mediterranean seagrass Posidonia oceanica meadows

The Distribution of Nickel in the West-Atlantic Ocean, Its Relationship With Phosphate and a Comparison to Cadmium and Zinc

The Potential Impact of Saharan Dust and Polluted Aerosols on Microbial Populations in the East Mediterranean Sea, an Overview of a Mesocosm Experimental Approach

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