Dissolved organic phosphorus regeneration by bacterioplankton: 5'-nucleotid-ase activity and subsequent phosphate uptake in a mesocosm enrichment experiment

Tamminen, Timo

doi:10.3354/meps058089

Cited by 39 publications

(21 citation statements)

References 13 publications

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“…This was in accordance with observations made by Tamminen (1989) who considered pico-and nanoplanktonic bacteria, algae and flagellates as playing an important role in the nutrient cycle.…”

Section: Processes During the Drift Experimentssupporting

confidence: 79%

Nutrient and plankton dynamics during a spring drift experiment in the German Bight

Raabe¹,

Brockmann²,

Dürselen³

et al. 1997

Mar. Ecol. Prog. Ser.

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The German Bight contains waters of mixed origin: freshwater input from the rivers Elbe, Ems and Weser, Wadden Sea water that is rich in organic compounds, and highly saline water (>33 SU) from the central North Sea. In order to investigate the very complex biological and biogeochemical situation caused by the various types of fronts and different water bodies, a spring drift experiment was carried out in this area following a survey of 45 stations covering the German Bight. A typical springtime situation was found diatom blooms (blomasses >500 pg C I-' in the mouth of the river Elbe) had decreased the silicate to around 0.3 pM; phosphate concentrations (~0 . 0 3 FM) were limiting primary production in the northeastern part of the investigated area, but, due to remineralization processes and riverine entrainment, they showed higher values in the south and in the river Elbe mouth (s0.3 FM).Nitrate ranged from 10 to 40 ~.IM and was clearly dominated by the river Elbe input. From the southwest a beginning bloom of Phaeocystis globosa spread into the dnft area and, later on, into the whole German Bight. Zooplankton biomass was highest along the North Frisian coast (>50 pg C I-'), and was dominated by copepods at the northwestern border of the German Bight and in the drift area. During the drift experiment, 2 phases and a transition state could be distinguished: In the first phase, the total phytoplankton biomass was low and nutrient concentrations remained relatively constant. In the transition state, strong wmd forces moved the dnfter southwards into another water body. A significant drop in nitrate, nitrite and phosphate concentrations was observed, whereas silicate concentrations almost doubled Dunng the second phase of the experiment, a strong increase of total phytoplankton biomass (cell slze >5 pm) was recorded, dominated by P. ylobosa (>95%) and accompanied by rising concentrations of particulate con~pounds. Simultaneously, the nutrient concentrations declined, and the zooplankton biomass reached minimum values. At a depth of 10 m, ammonium and phosphate concentrations showed strong diurnal variations, indicating enhanced planktonic activity during the third phase. Summing up the results, the overall evaluation of the drift experiment as a method for studying in situ biological and biogeochemical processes within the same water body was positive.

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“…This was in accordance with observations made by Tamminen (1989) who considered pico-and nanoplanktonic bacteria, algae and flagellates as playing an important role in the nutrient cycle.…”

Section: Processes During the Drift Experimentssupporting

confidence: 79%

Nutrient and plankton dynamics during a spring drift experiment in the German Bight

Raabe¹,

Brockmann²,

Dürselen³

et al. 1997

Mar. Ecol. Prog. Ser.

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“…These observations are consistent with the phosphohydrolytic activities of 5'-nucleotidase (Ammerman & Azam 1985), a ubiquitous enzyme of marine bacteria. This ectoenzyme has been shown to have the capacity to regenerate P at a rate that frequently vastly exceeds microbial P uptake rates (Siuda & Güde 1994) and has been hypothesized to provide sufficient P to satisfy microbial requirements (Tamminen 1989, Ammerman 1991. Consequently, dissolved nucleotides may be important in microbial metabolism, and the measurement of the fluxes of ATP and GTP through the microbial community could be a powerful tool for understanding interactions among the particulate and dissolved matter fractions, especially, but not exclusively, to the dynamics of the P pool.…”

Section: Discussionmentioning

confidence: 99%

Presence of dissolved nucleotides in the North Pacific Subtropical Gyre and their role in cycling of dissolved organic phosphorus

Björkman¹,

Karl²

2005

Aquat. Microb. Ecol.

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Dissolved and particulate nucleotide triphosphate (NTP) concentrations were measured in the upper 1000 m of the water column during 3 summer and 3 winter months at Stn ALOHA (22.75°N, 158°W) in the oligotrophic North Pacific Subtropical Gyre. In the euphotic zone (0 to 175 m) particulate adenosine-5'-triphosphate (P-ATP) and dissolved ATP (D-ATP) concentrations were positively correlated in summer (0 to 175 m; r 2 = 0.61, p < 0.001, n = 24), but not in winter (r 2 = 0.02, n = 24). D-ATP comprised > 65% of the total ATP (T-ATP) pool in the summer, and ~50% in winter. Dissolved guanosine-5'-triphosphate (D-GTP) inventories were 5-to 6-fold greater in July and August than those observed in mid-June (1.1 ± 0.1 vs. 8.0 ± 0.6 and 6.5 ± 0.3 µmol D-GTP m -2 , respectively) and winter concentrations were on average lower than the mean summer concentrations. The particulate GTP (P-GTP) inventories were almost twice those measured in winter (mean 1.1 ± 0.4 in summer vs. 0.6 ± 0.1 µmol P-GTP m -2 in winter, n = 3). These results are consistent with higher microbial growth rates in summer. Uptake of D-ATP showed multi-phasic kinetic patterns. The halfsaturation constants (K t ) ranged from 1 to 26 nM at D-ATP concentrations of 0.2 to 30 nM, and V max ranged from 0.3 to 1.4 nM d , and the turnover time of the ambient D-ATP pool was estimated to be 1 to 2 d. The P flux through the D-ATP pool could potentially be 5 times faster than that of the bulk DOP pool, implying that P derived from nucleotides may be an important pathway in the P cycle of oligotrophic oceans.

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“…Some studies in natural waters have, however, indicated that 5PN may mainly be associated with the bacterial size fraction (Ammerman & Azam (1985, 1991a. It has also been shown that some of the orthophosphate released by the membrane-bound 5PN may be taken up directly without intermediate mixing into the pool of free orthophosphate (Amrnerman & Azam 1985, 1991a, Tamminen 1989, thus potentially shifting the competition situation for phosphorus in favor of organisms possessing 5PN. A similar situation may exist for AP, although this enzyme is located in the periplasmatic space (Bengis-Garber & Kushner 1981, Thompson & McLeod 1974), and not in the membrane as may be the case with 5PN (Bengis-Garber 1985).…”

Section: Organic Substratesmentioning

confidence: 99%

Phosphorus cycling and algal-bacterial competition in Sandsfjord, western Norway

Thingstad¹,

Skjoldal²,

Bohne³

1993

Mar. Ecol. Prog. Ser.

247

164

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Microbial phosphorus-cycling, with particular emphasis on algal/bacterial competition, was studied in depth profiles through the halocline separating a brackish top layer, rich in nitrate and poor in phosphate, from the underlying coastal water, poor in both nitrate and phosphate, in the Sandsfjord area, western Norway. At 2 stations along the axis of natural freshwater outflow, physiological P-deficiency of algae and bacteria in the brackish layer was inferred from rapid luxury consumption of added PO: -by organisms in size fractions > l pm and 1-0.2 pm, respectively. In a branch of the fjord without natural freshwater outlets, luxury consumption in the brackish layer was less, and without a clear difference between the 2 water layers. High luxury consumption coincided with short (< 30 min) turnover times for ~0 2 -a n d strong bacterial dominance of 32P0,"--uptake, suggesting bacterial superiority as competitors during P-limiting conditions. Estimation of P-specific maximum uptake rate and affinity for PO:--uptake from isotope dilution experiments indicated bacterial superiority at low and algal superiority at high concentrations. Although most of the 32P hydrolyzed from added y -~T 3 2 P was initially liberated as free 32P04, partitioning of incorporated 32P between size fractions > l pm and 1-0.2 pm was found to depend on whether label was added as y -~T " P or as 3 2~0 , , -, indicating that coupling of uptake to hydrolysis by cell-bound enzymes could modify the outcome of algalbacterial phosphorus competition. Disappearance rate of "P from the 1-0.2 pm size fraction following initial labeling and a subsequent cold chase with PO:-, was used to estimate the flow-rate of phosphorus through the microbial food web. Combined with measured kinetic constants for PO: -uptake. alkaline phosphatases and 5'nucleotidases, a coherent flow-scheme could only be obtained assuming very low (< 1 nmol I-') concentrations of PO;'-and nucleotides. Chemically measured concentrations of dissolved organic phosphorus (DOP) more than 2 orders of magnitude above the estimated nucleotide level and with an estimated turnover time of ca 500 h, are consistent with the view that this large Preservoir consists mainly of slowly hydrolyzable polymers.

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Dissolved organic phosphorus regeneration by bacterioplankton: 5'-nucleotid-ase activity and subsequent phosphate uptake in a mesocosm enrichment experiment

Cited by 39 publications

References 13 publications

Nutrient and plankton dynamics during a spring drift experiment in the German Bight

Nutrient and plankton dynamics during a spring drift experiment in the German Bight

Presence of dissolved nucleotides in the North Pacific Subtropical Gyre and their role in cycling of dissolved organic phosphorus

Phosphorus cycling and algal-bacterial competition in Sandsfjord, western Norway

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