scholarly journals Phosphate and iron stress control global surface ocean dissolved organic phosphorus concentrations

2021 ◽  
Author(s):  
Zhou Liang ◽  
Robert Letscher ◽  
Angela Knapp
Keyword(s):  
Nitrogen Fixation ◽  
Primary Production ◽  
Organic Phosphorus ◽  
Control Surface ◽  
Global Ocean ◽  
Iron Stress ◽  
Dissolved Organic Phosphorus ◽  
Surface Ocean ◽  
Environmental Controls ◽  
Global Surface

Abstract Dissolved organic phosphorus (DOP) has a dual role in the surface ocean as both a product of primary production and as an organic nutrient fueling primary production and nitrogen fixation, especially in oligotrophic gyres. Though poorly constrained, understanding the geographic distribution and environmental controls of surface ocean DOP concentration is critical to estimating distributions and rates of primary production and nitrogen fixation in the global ocean. Here we pair DOP concentration measurements with a metric of phosphate (PO43−) stress (P*), and satellite-based chlorophyll a concentrations and iron stress estimates to explore their relationship with upper 50 m DOP stocks. Our results show that PO43− and iron stress work together to control surface DOP concentrations at basin scales. Specifically, upper 50 m DOP stocks decrease with increasing phosphate stress, while alleviated iron stress leads to either surface DOP accumulation or loss depending on PO43− availability. Our work suggests an interdependence between DOP concentration, inorganic nutrient ratios, and iron availability, and establishes a predictive framework for DOP distributions in the global surface ocean.

scholarly journals Phosphonate production by marine microbes: exploring new sources and potential function

2020 ◽  
Author(s):  
Marianne Acker ◽  
Shane L. Hogle ◽  
Paul M. Berube ◽  
Thomas Hackl ◽  
Ramunas Stepanauskas ◽  
...  
Keyword(s):  
Biological Function ◽  
Organic Phosphorus ◽  
Niche Partitioning ◽  
Low Frequency ◽  
Phosphorus Cycling ◽  
Global Ocean ◽  
Chemical Analyses ◽  
Marine Microbes ◽  
Surface Ocean ◽  
Phosphorus Source

AbstractPhosphonates, organic compounds with a C-P bond, constitute 20-25% of phosphorus in high molecular weight dissolved organic matter and are a significant phosphorus source for marine microbes. However, little is known about phosphonate sources, biological function, or biogeochemical cycling. Here, we determine the biogeographic distribution and prevalence of phosphonate biosynthesis potential using thousands of genomes and metagenomes from the upper 250 meters of the global ocean. Potential phosphonate producers are taxonomically diverse, occur in widely distributed and abundant marine lineages (including SAR11 and Prochlorococcus) and their abundance increases with depth. Within those lineages, phosphonate biosynthesis and catabolism pathways are mutually exclusive, indicating functional niche partitioning of organic phosphorus cycling in the marine microbiome. Surprisingly, one strain of Prochlorococcus (SB) can allocate more than 40% of its cellular P-quota towards phosphonate production. Chemical analyses and genomic evidence suggest that phosphonates in this strain are incorporated into surface layer glycoproteins that may act to reduce mortality from grazing or viral infection. Although phosphonate production is a low-frequency trait in Prochlorococcus populations (~ 5% of genomes), experimentally derived production rates suggest that Prochlorococcus could produce a significant fraction of the total phosphonate in the oligotrophic surface ocean. These results underscore the global biogeochemical impact of even relatively rare functional traits in abundant groups like Prochlorococcus and SAR11.

scholarly journals Sargasso Sea phosphorus biogeochemistry: an important role for dissolved organic phosphorus (DOP)

2010 ◽  
Vol 7 (2) ◽  
pp. 695-710 ◽  
Author(s):  
M. W. Lomas ◽  
A. L. Burke ◽  
D. A. Lomas ◽  
D. W. Bell ◽  
C. Shen ◽  
...  
Keyword(s):  
Time Series ◽  
Primary Production ◽  
North Atlantic ◽  
Spring Bloom ◽  
Organic Phosphorus ◽  
Seasonal Pattern ◽  
Euphotic Zone ◽  
Inorganic Phosphorus ◽  
Dissolved Organic Phosphorus ◽  
Phosphorus Export

Abstract. Inorganic phosphorus (SRP) concentrations in the subtropical North Atlantic are some of the lowest in the global ocean and have been hypothesized to constrain primary production. Based upon data from several transect cruises in this region, it has been hypothesized that dissolved organic phosphorus (DOP) supports a significant fraction of primary production in the subtropical North Atlantic. In this study, a time-series of phosphorus biogeochemistry is presented for the Bermuda Atlantic Time-series Study site, including rates of phosphorus export. Most parameters have a seasonal pattern, although year-over-year variability in the seasonal pattern is substantial, likely due to differences in external forcing. Suspended particulate phosphorus exhibits a seasonal maximum during the spring bloom, despite the absence of a seasonal peak in SRP. However, DOP concentrations are at an annual maximum prior to the winter/spring bloom and decline over the course of the spring bloom while whole community alkaline phosphatase activities are highest. As a result of DOP bioavailability, the growth of particles during the spring bloom occurs in Redfield proportions, though particles exported from the euphotic zone show rapid and significant remineralization of phosphorus within the first 50 m below the euphotic zone. Based upon DOP data from transect cruises in this region, the southward cross gyral flux of DOP is estimated to support ~25% of annual primary production and ~100% of phosphorus export. These estimates are consistent with other research in the subtropical North Atlantic and reinforce the hypothesis that while the subtropics may be phosphorus stressed (a physiological response to low inorganic phosphorus), utilization of the DOP pool allows production and accumulation of microbial biomass at Redfield proportions.

scholarly journals Stable Abiotic Production of Ammonia from Nitrate in Komatiite-Hosted Hydrothermal Systems in the Hadean and Archean Oceans

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 321
Author(s):  
Manabu Nishizawa ◽  
Takuya Saito ◽  
Akiko Makabe ◽  
Hisahiro Ueda ◽  
Masafumi Saitoh ◽  
...  
Keyword(s):  
Biological Evolution ◽  
Subsequent Development ◽  
Hydrothermal Systems ◽  
Global Ocean ◽  
Surface Ocean ◽  
Chemosynthetic Ecosystems ◽  
Global Surface ◽  
Ammonia Flux ◽  
Production Of Ammonia

Abiotic fixation of atmospheric dinitrogen to ammonia is important in prebiotic chemistry and biological evolution in the Hadean and Archean oceans. Though it is widely accepted that nitrate (NO3−) was generated in the early atmospheres, the stable pathways of ammonia production from nitrate deposited in the early oceans remain unknown. This paper reports results of the first experiments simulating high-temperature, high-pressure reactions between nitrate and komatiite to find probable chemical pathways to deliver ammonia to the vent–ocean interface of komatiite-hosted hydrothermal systems and the global ocean on geological timescales. The fluid chemistry and mineralogy of the komatiite–H2O–NO3− system show iron-mediated production of ammonia from nitrate with yields of 10% at 250 °C and 350 °C, 500 bars. The komatiite–H2O–NO3– system also generated H2-rich and alkaline fluids, well-known prerequisites for prebiotic and primordial metabolisms, at lower temperatures than the komatiite–H2O–CO2 system. We estimate the ammonia flux from the komatiite-hosted systems to be 105–1010 mol/y in the early oceans. If the nitrate concentration in the early oceans was greater than 10 μmol/kg, the long-term production of ammonia through thermochemical nitrate reduction for the first billion years might have allowed the subsequent development of an early biosphere in the global surface ocean. Our results imply that komatiite-hosted systems might have impacted not only H2-based chemosynthetic ecosystems at the vent-ocean interface but also photosynthetic ecosystems on the early Earth.

scholarly journals Sargasso Sea phosphorus biogeochemistry: an important role for dissolved organic phosphorus (DOP)

2009 ◽  
Vol 6 (5) ◽  
pp. 10137-10175 ◽  
Author(s):  
M. W. Lomas ◽  
A. L. Burke ◽  
D. A. Lomas ◽  
D. W. Bell ◽  
C. Shen ◽  
...  
Keyword(s):  
Time Series ◽  
Primary Production ◽  
North Atlantic ◽  
Spring Bloom ◽  
Organic Phosphorus ◽  
Seasonal Pattern ◽  
Euphotic Zone ◽  
Inorganic Phosphorus ◽  
Dissolved Organic Phosphorus ◽  
Phosphorus Export

Abstract. Inorganic phosphorus (SRP) concentrations in the subtropical North Atlantic are some of the lowest in the global ocean and have been hypothesized to constrain primary production. Based upon data from several transect cruises in this region, it has been hypothesized that dissolved organic phosphorus (DOP) supports a significant fraction of primary production. In this study, a time-series of phosphorus biogeochemistry is presented for the Bermuda Atlantic Time-series Study site, including rates of phosphorus export. Most parameters have a seasonal pattern, although year-over-year variability in the seasonal pattern is substantial, likely due to differences in external forcing. Suspended particulate phosphorus exhibits a seasonal maximum during the spring bloom, despite the absence of a seasonal peak in SRP. However, DOP concentrations are at an annual maximum prior to the winter/spring bloom and decline over the course of the spring bloom while whole community alkaline phosphatase activities are highest. As a result of DOP bioavailability, the growth of particles during the spring bloom occurs in Redfield proportions, though particles exported from the euphotic zone show rapid and significant remineralization of phosphorus within the first 50 m below the euphotic zone. Based upon DOP data from transect cruises in this region, the southward cross gyral flux of DOP is estimated to support ~32% of annual primary production and ~100% of phosphorus export. These estimates are consistent with other research in the subtropical North Atlantic and reinforce the hypothesis that while the subtropics may be phosphorus stressed (a physiological response to low inorganic phosphorus), utilization of the DOP pool allows production and accumulation of microbial biomass at Redfield proportions.

scholarly journals Surface ocean pH and buffer capacity: past, present and future

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Li-Qing Jiang ◽  
Brendan R. Carter ◽  
Richard A. Feely ◽  
Siv K. Lauvset ◽  
Are Olsen
Keyword(s):  
Spatial Variability ◽  
Buffer Capacity ◽  
Temporal Trends ◽  
Dominant Mode ◽  
Global Ocean ◽  
Intergovernmental Panel ◽  
Surface Ocean ◽  
Anthropogenic Carbon ◽  
Data Coverage ◽  
Global Surface

AbstractThe ocean’s chemistry is changing due to the uptake of anthropogenic carbon dioxide (CO2). This phenomenon, commonly referred to as “Ocean Acidification”, is endangering coral reefs and the broader marine ecosystems. In this study, we combine a recent observational seawater CO2 data product, i.e., the 6th version of the Surface Ocean CO2 Atlas (1991–2018, ~23 million observations), with temporal trends at individual locations of the global ocean from a robust Earth System Model to provide a high-resolution regionally varying view of global surface ocean pH and the Revelle Factor. The climatology extends from the pre-Industrial era (1750 C.E.) to the end of this century under historical atmospheric CO2 concentrations (pre-2005) and the Representative Concentrations Pathways (post-2005) of the Intergovernmental Panel on Climate Change (IPCC)’s 5th Assessment Report. By linking the modeled pH trends to the observed modern pH distribution, the climatology benefits from recent improvements in both model design and observational data coverage, and is likely to provide improved regional OA trajectories than the model output could alone, therefore, will help guide the regional OA adaptation strategies. We show that air-sea CO2 disequilibrium is the dominant mode of spatial variability for surface pH, and discuss why pH and calcium carbonate mineral saturation states, two important metrics for OA, show contrasting spatial variability.

scholarly journals Non-Conventional Metal Ion Cofactor Requirement of Dinoflagellate Alkaline Phosphatase and Translational Regulation by Phosphorus Limitation

2019 ◽  
Vol 7 (8) ◽  
pp. 232 ◽  
Author(s):  
Xin Lin ◽  
Chentao Guo ◽  
Ling Li ◽  
Tangcheng Li ◽  
Senjie Lin
Keyword(s):  
Alkaline Phosphatase ◽  
Metal Ion ◽  
Translational Regulation ◽  
Organic Phosphorus ◽  
Niche Differentiation ◽  
Phosphorus Limitation ◽  
Marine Phytoplankton ◽  
Phosphate Limitation ◽  
Dissolved Organic Phosphorus ◽  
Metal Cofactor

Alkaline phosphatase (AP) enables marine phytoplankton to utilize dissolved organic phosphorus (DOP) when dissolved inorganic phosphate (DIP) is depleted in the ocean. Dinoflagellate AP (Dino-AP) represents a newly classified atypical type of AP, PhoAaty. Despite While being a conventional AP, PhoAEC is known to recruit Zn2+ and Mg2+ in the active center, and the cofactors required by PhoAaty have been contended and remain unclear. In this study, we investigated the metal ion requirement of AP in five dinoflagellate species. After AP activity was eliminated by using EDTA to chelate metal ions, the enzymatic activity could be recovered by the supplementation of Ca2+, Mg2+ and Mn2+ in all cases but not by that of Zn2+. Furthermore, the same analysis conducted on the purified recombinant ACAAP (AP of Amphidinium carterae) verified that the enzyme could be activated by Ca2+, Mg2+, and Mn2+ but not Zn2+. We further developed an antiserum against ACAAP, and a western blot analysis using this antibody showed a remarkable up-regulation of ACAAP under a phosphate limitation, consistent with elevated AP activity. The unconventional metal cofactor requirement of Dino-AP may be an adaptation to trace metal limitations in the ocean, which warrants further research to understand the niche differentiation between dinoflagellates and other phytoplankton that use Zn–Mg AP in utilizing DOP.

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