The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Sonya T. Dyhrman - One of the best experts on this subject based on the ideXlab platform.
-
Dissolved Organic Phosphorus Production during Simulated Phytoplankton Blooms in a Coastal Upwelling System.
Frontiers in microbiology, 2012Co-Authors: Kathleen C. Ruttenberg, Sonya T. DyhrmanAbstract:Dissolved Organic Phosphorus (DOP) is increasingly recognized as an important Phosphorus source that can support primary production in a variety of marine systems. Despite its importance, the production rate and fate of DOP is poorly understood. In this study, four shipboard nutrient addition experiments were conducted during the upwelling summer season off the coast of Oregon (USA) to track DOP production. Nitrogen (N) and Phosphorus (P) additions were used to decouple DOP production and hydrolysis by inducing or repressing, respectively, community alkaline phosphatase activity. In order to examine the progression of nutrient uptake and DOP production under upwelling versus relaxation conditions, two experiments were initiated with waters collected during upwelling events, and two with waters collected during relaxation events. Increases in DOP concentration occurred by day-5 in control treatments in all experiments. Nitrogen treatments had increased chlorophyll a, and yielded lower net DOP production rates relative to controls, as well as increased alkaline phosphatase activity, suggesting that DOP levels were depressed as a consequence of increased hydrolysis of bioavailable DOP substrates. Phosphorus additions resulted in a significant net production of DOP at all stations, but no increase in chlorophyll a relative to control treatments. Taken together these data suggest that changes in DIN:DIP will influence DOP production, which in turn may impact the potential export of DOP to offshore ecosystems. A comparison of experimental data from the four sites also suggests that geographic/physiographic conditions exert greater control on DOP production than physical (upwelling versus relaxation) conditions.
-
Quorum sensing control of Phosphorus acquisition in Trichodesmium consortia.
The ISME Journal, 2011Co-Authors: Benjamin A. S. Van Mooy, Sonya T. Dyhrman, Laura R. Hmelo, Laura E Sofen, Shawn R. Campagna, Amanda L. May, Abigail Heithoff, Eric A. Webb, Lily Momper, Tracy J. MincerAbstract:Colonies of the cyanobacterium Trichodesmium are abundant in the oligotrophic ocean, and through their ability to fix both CO2 and N2, have pivotal roles in the cycling of carbon and nitrogen in these highly nutrient-depleted environments. Trichodesmium colonies host complex consortia of epibiotic heterotrophic bacteria, and yet, the regulation of nutrient acquisition by these epibionts is poorly understood. We present evidence that epibiotic bacteria in Trichodesmium consortia use quorum sensing (QS) to regulate the activity of alkaline phosphatases (APases), enzymes used by epibionts in the acquisition of phosphate from Dissolved-Organic Phosphorus molecules. A class of QS molecules, acylated homoserine lactones (AHLs), were produced by cultivated epibionts, and adding these AHLs to wild Trichodesmium colonies collected at sea led to a consistent doubling of APase activity. By contrast, amendments of (S)-4,5-dihydroxy-2,3-pentanedione (DPD)—the precursor to the autoinducer-2 (AI-2) family of universal interspecies signaling molecules—led to the attenuation of APase activity. In addition, colonies collected at sea were found by high performance liquid chromatography/mass spectrometry to contain both AHLs and AI-2. Both types of molecules turned over rapidly, an observation we ascribe to quorum quenching. Our results reveal a complex chemical interplay among epibionts using AHLs and AI-2 to control access to phosphate in Dissolved-Organic Phosphorus.
-
Sargasso Sea Phosphorus biogeochemistry: an important role for Dissolved Organic Phosphorus (DOP)
Biogeosciences, 2010Co-Authors: Michael W. Lomas, Sonya T. Dyhrman, A. L. Burke, D. A. Lomas, Douglas W. Bell, Chenchen Shen, James W. AmmermanAbstract: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.
-
A microbial source of phosphonates in oligotrophic marine systems
Nature Geoscience, 2009Co-Authors: Sonya T. Dyhrman, Claudia R. Benitez-nelson, Elizabeth D. Orchard, Sheean T. Haley, Perry J. PellechiaAbstract:Phosphonates, compounds with a carbon–Phosphorus bond, are a key component of the marine-Dissolved Organic Phosphorus pool. Nuclear magnetic resonance spectroscopy measurements suggest that the cyanobacteria Trichodesmium is a significant source of phosphonates in nutrient-poor regions of the ocean. Phosphonates, compounds with a carbon–Phosphorus bond, are a key component of the marine Dissolved Organic Phosphorus pool1. These compounds serve as a Phosphorus source for primary producers, including the nitrogen-fixing cyanobacteria Trichodesmium2. Phosphonates can therefore support marine primary production, as well as climate-driven increases in marine nitrogen fixation3, carbon sequestration4 and possibly methane production, through the breakdown of methylphosphonate5. Despite their importance, the source of phosphonates to the open ocean has remained uncertain. Here, we use solid-state nuclear magnetic resonance spectroscopy to screen for the presence of phosphonates in cultured strains of Trichodesmium erythraeum. We show that phosphonates comprise an average of 10% of the cellular particulate Phosphorus pool in this species. We therefore suggest that these cyanobacteria produce phosphonates, and might be a significant source of these compounds in the ocean, particularly in nutrient-poor regions, where Trichodesmium blooms occur. Given that Trichodesmium also thrives in a warm, carbon-dioxide-rich environment3, phosphonate production may increase in the future. This, in turn, might select for a microbial community that can use phosphonate, and could have implications for nitrogen fixation, carbon sequestration and greenhouse-gas production.
-
presence and regulation of alkaline phosphatase activity in eukaryotic phytoplankton from the coastal ocean implications for Dissolved Organic Phosphorus remineralization
Limnology and Oceanography, 2006Co-Authors: Sonya T. Dyhrman, Kathleen C. RuttenbergAbstract:The biologically important constituents of the Dissolved Organic Phosphorus (DOP) pool, their bioavailability, and their cycling in coastal systems are still poorly understood. Here we use the enzyme alkaline phosphatase as a metric of DOP bioavailability and track the activity of this enzyme in a coastal system. We observed alkaline phosphatase activity (APA) in the >0.2-μm size fraction of all surface samples tested during an Oregon coast cruise in August 2001. Although there was not a significant trend between APA and phosphate concentration in the data set as a whole, chlorophyll a-normalized APA was elevated at the station with the lowest Dissolved inOrganic phosphate (DIP) concentration. Activity was also elevated in nutrient-addition experiments in which nitrate amendments were Used to force community drawdown of DIP. These data are consistent with phosphate regulation of APA. A cell-specific APA assay revealed that the percentage of diatoms with APA mimicked the trend in the hydrolytic rate, but such a trend was not observed for the dinoflagellates. Further, the percentage of dinoflagellate cells with APA was routinely higher than the percentage of diatom cells with activity. In nutrient-addition experiments designed to evaluate the regulation of APA, diatom taxa expressed APA less frequently than dinoflagellates, but they displayed a tighter regulation of the activity by DIP than dinoflagellates. The variability observed in the presence and regulation of APA in these eukaryotic phytoplankton indicates that DOP bioavailability is a potential driver of phytoplankton nutrition and species composition in the coastal ocean.
Douglas W. Bell - One of the best experts on this subject based on the ideXlab platform.
-
isolation and molecular characterization of Dissolved Organic Phosphorus using electrodialysis reverse osmosis and solution 31p nmr
Limnology and Oceanography-methods, 2017Co-Authors: Douglas W. Bell, Perry Pellechia, Luke R. Chambers, Amelia F. Longo, Kelly M. Mccabe, Ellery D. Ingall, Claudia BeniteznelsonAbstract:The composition of Dissolved Organic Phosphorus (DOP), which directly impacts its biological and chemical reactivity, remains poorly constrained due to methodological and operational challenges. A series of compound-specific isolation experiments and bulk estuarine seawater isolations were conducted to assess the ability of coupled electrodialysis (ED) and reverse osmosis (RO) to isolate DOP from seawater for molecular characterization using solution 31P-NMR analysis. These isolations were carried out using a recently developed small-volume (24 L) ED/RO system. Compound-specific isolation experiments (n = 7) averaged 64.1% ± 9.2% for final DOP recovery, while recoveries for estuarine seawater (n = 7) were on average 83.8% ± 10.7%. Nearly complete mass balance of DOP was observed for the compound-specific isolations (88.1% ± 11.2%) with ED responsible for the majority of DOP loss (16% ± 5%). Isolation recovery was impacted by compound molecular weight rather than charge-to-size ratio. Isolation bias between bulk Dissolved Organic carbon and DOP was negligible. Solution 31P-NMR confirmed that ED/RO isolation does not impact molecular integrity or DOP composition. In addition, solution 31P-NMR accurately estimated several components (phosphonomethyl-glycine, D-glucose-6-phosphate, L-α-phosphatidylcholine) of an artificial complex DOP matrix. However, we suggest further refinements for ED/RO operation and significant caveats remain for 31P-NMR sample preparation and the interpretation of 31P-NMR spectra. Hydrolysis from NaOH dissolution was found to impact the ability to accurately resolve diester composition (ca. 40% underestimation) and discrimination between terminal and central phosphoanhydride atoms. Nonetheless, our results describe a viable option for the isolation and molecular characterization of marine DOP.
-
Isolation and molecular characterization of Dissolved Organic Phosphorus using electrodialysis‐reverse osmosis and solution 31P‐NMR
Limnology and Oceanography: Methods, 2017Co-Authors: Douglas W. Bell, Perry Pellechia, Luke R. Chambers, Amelia F. Longo, Kelly M. Mccabe, Ellery D. Ingall, Claudia Benitez-nelsonAbstract:The composition of Dissolved Organic Phosphorus (DOP), which directly impacts its biological and chemical reactivity, remains poorly constrained due to methodological and operational challenges. A series of compound-specific isolation experiments and bulk estuarine seawater isolations were conducted to assess the ability of coupled electrodialysis (ED) and reverse osmosis (RO) to isolate DOP from seawater for molecular characterization using solution 31P-NMR analysis. These isolations were carried out using a recently developed small-volume (24 L) ED/RO system. Compound-specific isolation experiments (n = 7) averaged 64.1% ± 9.2% for final DOP recovery, while recoveries for estuarine seawater (n = 7) were on average 83.8% ± 10.7%. Nearly complete mass balance of DOP was observed for the compound-specific isolations (88.1% ± 11.2%) with ED responsible for the majority of DOP loss (16% ± 5%). Isolation recovery was impacted by compound molecular weight rather than charge-to-size ratio. Isolation bias between bulk Dissolved Organic carbon and DOP was negligible. Solution 31P-NMR confirmed that ED/RO isolation does not impact molecular integrity or DOP composition. In addition, solution 31P-NMR accurately estimated several components (phosphonomethyl-glycine, D-glucose-6-phosphate, L-α-phosphatidylcholine) of an artificial complex DOP matrix. However, we suggest further refinements for ED/RO operation and significant caveats remain for 31P-NMR sample preparation and the interpretation of 31P-NMR spectra. Hydrolysis from NaOH dissolution was found to impact the ability to accurately resolve diester composition (ca. 40% underestimation) and discrimination between terminal and central phosphoanhydride atoms. Nonetheless, our results describe a viable option for the isolation and molecular characterization of marine DOP.
-
Sargasso Sea Phosphorus biogeochemistry: an important role for Dissolved Organic Phosphorus (DOP)
Biogeosciences, 2010Co-Authors: Michael W. Lomas, Sonya T. Dyhrman, A. L. Burke, D. A. Lomas, Douglas W. Bell, Chenchen Shen, James W. AmmermanAbstract: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.
-
Sargasso Sea Phosphorus biogeochemistry: an important role for Dissolved Organic Phosphorus (DOP)
2009Co-Authors: Michael W. Lomas, A. L. Burke, D. A. Lomas, Douglas W. Bell, Chenchen Shen, S. T. Dyhrman, J.w. AmmermanAbstract: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.
Kathleen C. Ruttenberg - One of the best experts on this subject based on the ideXlab platform.
-
Dissolved Organic Phosphorus Production during Simulated Phytoplankton Blooms in a Coastal Upwelling System.
Frontiers in microbiology, 2012Co-Authors: Kathleen C. Ruttenberg, Sonya T. DyhrmanAbstract:Dissolved Organic Phosphorus (DOP) is increasingly recognized as an important Phosphorus source that can support primary production in a variety of marine systems. Despite its importance, the production rate and fate of DOP is poorly understood. In this study, four shipboard nutrient addition experiments were conducted during the upwelling summer season off the coast of Oregon (USA) to track DOP production. Nitrogen (N) and Phosphorus (P) additions were used to decouple DOP production and hydrolysis by inducing or repressing, respectively, community alkaline phosphatase activity. In order to examine the progression of nutrient uptake and DOP production under upwelling versus relaxation conditions, two experiments were initiated with waters collected during upwelling events, and two with waters collected during relaxation events. Increases in DOP concentration occurred by day-5 in control treatments in all experiments. Nitrogen treatments had increased chlorophyll a, and yielded lower net DOP production rates relative to controls, as well as increased alkaline phosphatase activity, suggesting that DOP levels were depressed as a consequence of increased hydrolysis of bioavailable DOP substrates. Phosphorus additions resulted in a significant net production of DOP at all stations, but no increase in chlorophyll a relative to control treatments. Taken together these data suggest that changes in DIN:DIP will influence DOP production, which in turn may impact the potential export of DOP to offshore ecosystems. A comparison of experimental data from the four sites also suggests that geographic/physiographic conditions exert greater control on DOP production than physical (upwelling versus relaxation) conditions.
-
presence and regulation of alkaline phosphatase activity in eukaryotic phytoplankton from the coastal ocean implications for Dissolved Organic Phosphorus remineralization
Limnology and Oceanography, 2006Co-Authors: Sonya T. Dyhrman, Kathleen C. RuttenbergAbstract:The biologically important constituents of the Dissolved Organic Phosphorus (DOP) pool, their bioavailability, and their cycling in coastal systems are still poorly understood. Here we use the enzyme alkaline phosphatase as a metric of DOP bioavailability and track the activity of this enzyme in a coastal system. We observed alkaline phosphatase activity (APA) in the >0.2-μm size fraction of all surface samples tested during an Oregon coast cruise in August 2001. Although there was not a significant trend between APA and phosphate concentration in the data set as a whole, chlorophyll a-normalized APA was elevated at the station with the lowest Dissolved inOrganic phosphate (DIP) concentration. Activity was also elevated in nutrient-addition experiments in which nitrate amendments were Used to force community drawdown of DIP. These data are consistent with phosphate regulation of APA. A cell-specific APA assay revealed that the percentage of diatoms with APA mimicked the trend in the hydrolytic rate, but such a trend was not observed for the dinoflagellates. Further, the percentage of dinoflagellate cells with APA was routinely higher than the percentage of diatom cells with activity. In nutrient-addition experiments designed to evaluate the regulation of APA, diatom taxa expressed APA less frequently than dinoflagellates, but they displayed a tighter regulation of the activity by DIP than dinoflagellates. The variability observed in the presence and regulation of APA in these eukaryotic phytoplankton indicates that DOP bioavailability is a potential driver of phytoplankton nutrition and species composition in the coastal ocean.
-
temporal and spatial variability of Dissolved Organic and inOrganic Phosphorus and metrics of Phosphorus bioavailability in an upwelling dominated coastal system
Journal of Geophysical Research, 2005Co-Authors: Kathleen C. Ruttenberg, Sonya T. DyhrmanAbstract:1). Spatial and temporal variability are also evident in phytoplankton community composition and in APA. The spatial pattern of Dissolved Phosphorus and APAvariability can be explained by bottom-controlled patterns of upwelling, and flushing times of different regions within the study area. The presence of APA in eukaryotic taxa indicates that Dissolved Organic Phosphorus (DOP) may contribute to phytoplankton P nutrition in this system, highlighting the need for a more complete understanding of P cycling and bioavailability in the coastal ocean.
-
Temporal and spatial variability of Dissolved Organic and inOrganic Phosphorus, and metrics of Phosphorus bioavailability in an upwelling‐dominated coastal system
Journal of Geophysical Research, 2005Co-Authors: Kathleen C. Ruttenberg, Sonya T. DyhrmanAbstract:1). Spatial and temporal variability are also evident in phytoplankton community composition and in APA. The spatial pattern of Dissolved Phosphorus and APAvariability can be explained by bottom-controlled patterns of upwelling, and flushing times of different regions within the study area. The presence of APA in eukaryotic taxa indicates that Dissolved Organic Phosphorus (DOP) may contribute to phytoplankton P nutrition in this system, highlighting the need for a more complete understanding of P cycling and bioavailability in the coastal ocean.
-
Dissolved Organic Phosphorus in the coastal ocean: Reassessment of available methods and seasonal Phosphorus profiles from the Eel River Shelf
Limnology and Oceanography, 1999Co-Authors: E. J. Monaghan, Kathleen C. RuttenbergAbstract:Methods for quantifying total Dissolved Phosphorus (TDP) were reevaluated. High-temperature ashing/hydrolysis (Ash/Hydrol.) and Acid Persulfate methods were examined for their ability to quantitatively convert a range of Organic-P compounds to orthophosphate. The Ash/Hydrol. method recovered on average 99% of Organic-P compounds tested, including phosphonates (compounds with C-P bonds). Contrary to concerns voiced in prior studies, we found no P loss due to volatilization in seawater samples. Poor recovery by the Acid Persulfate method was observed for two compound classes: phosphonates and phospholipids. The Ash/Hydrol. method is recommended for routine TDP analyses. The hydrolysis of Dissolved Organic Phosphorus (DOP) during the phosphomolybdate-blue reaction and the subsequent overestimation of Dissolved inOrganic Phosphorus (DIP) have long been a concern. Extent of hydrolysis of standard DOP compounds was evaluated both during this reaction and over long-term acidified (pH 1.0)/refrigerated and unacidified/frozen storage. Eleven of 12 compounds tested hydrolyzed,2% during the phosphomolybdate-blue reaction. Phospholipid, phosphosugar, and nucleotide mono- and diphosphate standards stored acidified/refrigerated over 2.5 months were ,5% hydrolyzed; compounds with higher energy phosphate bonds (e.g., phosphocreatine) hydrolyzed to a greater extent. A natural seawater sample showed no hydrolysis over 80 d, however, suggesting that refrigerated storage of acidified samples is a viable option. Seasonal DOP profiles from the Eel River Shelf quantified by the Ash/Hydrol. and Acid Persulfate methods yielded comparable results, indicating that the DOP pool at this site did not contain significant phospholipids or phosphonates, which are underrecovered by the Persulfate method. Recoveries using a third method, Nitrate Oxidation, were on average 7% lower. Surface-water DOP exceeded DIP in summer and was apparently related to biological productivity, underscoring the need to include Organic species when evaluating nutrient limitation and creating nutrient budgets.
Huasheng Hong - One of the best experts on this subject based on the ideXlab platform.
-
Bioavailability of Dissolved Organic Phosphorus compounds to typical harmful dinoflagellate Prorocentrum donghaiense Lu.
Marine pollution bulletin, 2005Co-Authors: Bangqin Huang, Huasheng Hong, Haiwei Luo, Dazhi WangAbstract:The bioavailability of Dissolved Organic Phosphorus (DOP) compounds to harmful alga Prorocentrum donghaiense Lu and its alkaline phosphatase activity (APA) were studied. Results showed that P. donghaiense could utilize the test DOP compounds such as glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP) and ribonucleic acid (RNA) to sustain its growth. Nutrition between the test DOP compounds and orthophosphate was comparable. P. donghaiense could utilize intracellular Phosphorus to sustain growth under depletion of Dissolved Phosphorus. Variation of APA in different test DOP compounds was addressed; the controlling mechanism of APA in different DOP media was discussed.
-
Alkaline phosphatase activity and utilization of Dissolved Organic Phosphorus by algae in subtropical coastal waters
Marine Pollution Bulletin, 1999Co-Authors: Bangqin Huang, Huasheng HongAbstract:Alkaline phosphatase activity (APA) and the availability of Dissolved Organic Phosphorus (DOP) to marine algae were determined in Xiamen Bay and in algal batch culture systems. Results showed that APA changed with seasons, increasing to the highest value in summer and decreasing to the lowest in autumn and spring in Xiamen Bay. Tests on natural populations of planktonic algae and bacteria community showed that algae were mostly responsible for DOP utilization, while bacteria could not take up DOP compounds. Results from algal batch cultures also supported the above conclusion. Relationships between APA and environmental factors indicated that APA was negatively correlated with Phosphorus level such as phosphate and small molecular DOP, and APA played an important role in utilization of DOP by algae. All the results emphasized the ecological significance of DOP in subtropical coastal waters.
-
Alkaline Phosphatase Activity and Utilization of Dissolved Organic Phosphorus by Algae in Subtropical Coastal Waters
Marine Pollution Bulletin, 1999Co-Authors: Bangqin Huang, Huasheng HongAbstract:Alkaline phosphatase activity (APA) and the availability of Dissolved Organic Phosphorus (DOP) to marine algae were determined in Xiamen Bay and in algal batch culture systems. Results showed that APA changed with seasons, increasing to the highest value in summer and decreasing to the lowest in autumn and spring in Xiamen Bay. Tests on natural populations of planktonic algae and bacteria community showed that algae were mostly responsible for DOP utilization, while bacteria could not take up DOP compounds. Results from algal batch cultures also supported the above conclusion. Relationships between APA and environmental factors indicated that APA was negatively correlated with Phosphorus level such as phosphate and small molecular DOP, and APA played an important role in utilization of DOP by algae. All the results emphasized the ecological significance of DOP in subtropical coastal waters. (C) 1999 Elsevier Science Ltd. All rights reserved
Bangqin Huang - One of the best experts on this subject based on the ideXlab platform.
-
Bioavailability of Dissolved Organic Phosphorus compounds to typical harmful dinoflagellate Prorocentrum donghaiense Lu.
Marine pollution bulletin, 2005Co-Authors: Bangqin Huang, Huasheng Hong, Haiwei Luo, Dazhi WangAbstract:The bioavailability of Dissolved Organic Phosphorus (DOP) compounds to harmful alga Prorocentrum donghaiense Lu and its alkaline phosphatase activity (APA) were studied. Results showed that P. donghaiense could utilize the test DOP compounds such as glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP) and ribonucleic acid (RNA) to sustain its growth. Nutrition between the test DOP compounds and orthophosphate was comparable. P. donghaiense could utilize intracellular Phosphorus to sustain growth under depletion of Dissolved Phosphorus. Variation of APA in different test DOP compounds was addressed; the controlling mechanism of APA in different DOP media was discussed.
-
Alkaline phosphatase activity and utilization of Dissolved Organic Phosphorus by algae in subtropical coastal waters
Marine Pollution Bulletin, 1999Co-Authors: Bangqin Huang, Huasheng HongAbstract:Alkaline phosphatase activity (APA) and the availability of Dissolved Organic Phosphorus (DOP) to marine algae were determined in Xiamen Bay and in algal batch culture systems. Results showed that APA changed with seasons, increasing to the highest value in summer and decreasing to the lowest in autumn and spring in Xiamen Bay. Tests on natural populations of planktonic algae and bacteria community showed that algae were mostly responsible for DOP utilization, while bacteria could not take up DOP compounds. Results from algal batch cultures also supported the above conclusion. Relationships between APA and environmental factors indicated that APA was negatively correlated with Phosphorus level such as phosphate and small molecular DOP, and APA played an important role in utilization of DOP by algae. All the results emphasized the ecological significance of DOP in subtropical coastal waters.
-
Alkaline Phosphatase Activity and Utilization of Dissolved Organic Phosphorus by Algae in Subtropical Coastal Waters
Marine Pollution Bulletin, 1999Co-Authors: Bangqin Huang, Huasheng HongAbstract:Alkaline phosphatase activity (APA) and the availability of Dissolved Organic Phosphorus (DOP) to marine algae were determined in Xiamen Bay and in algal batch culture systems. Results showed that APA changed with seasons, increasing to the highest value in summer and decreasing to the lowest in autumn and spring in Xiamen Bay. Tests on natural populations of planktonic algae and bacteria community showed that algae were mostly responsible for DOP utilization, while bacteria could not take up DOP compounds. Results from algal batch cultures also supported the above conclusion. Relationships between APA and environmental factors indicated that APA was negatively correlated with Phosphorus level such as phosphate and small molecular DOP, and APA played an important role in utilization of DOP by algae. All the results emphasized the ecological significance of DOP in subtropical coastal waters. (C) 1999 Elsevier Science Ltd. All rights reserved