Fluctuation of algal alkaline phosphatase activity and the possible mechanisms of hydrolysis of dissolved organic phosphorus in Lake Barato

Hydrobiologia ◽  
1988 ◽  
Vol 157 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Shuji Hino
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Organic Phosphorus ◽  
Dissolved Organic Phosphorus ◽  
Hydrolysis Of

scholarly journals A Comparison of Human Leukocyte Phosphatase Activity toward Sodium β-Glycerophosphate, Adenosine 5'-Phosphate and Glucose 1-Phosphate

Blood ◽  
1959 ◽  
Vol 14 (4) ◽  
pp. 415-422 ◽  
Author(s):  
JAMES H. FOLLETTE ◽  
WILLIAM N. VALENTINE ◽  
JOHN REYNOLDS
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Cell Population ◽  
Alkaline Phosphatase Activity ◽  
Human Leukocyte ◽  
Maximal Activity ◽  
Phosphate Esters ◽  
Chronic Myelocytic Leukemia ◽  
Myelocytic Leukemia ◽  
Hydrolysis Of

Abstract The ability of human leukocyte enzymes to hydrolyze phosphorus is compared in terms of the conventional substrate sodium β-glycerophosphate and the metabolically important phosphate esters, adenosine 5'-phosphate and glucose 1-phosphate. At pH 9.9, there is marked and comparable variation in phosphatase activity toward all three substrates, this being low in chronic myelocytic leukemia and high in the presence of infection and certain "stressful" states. Moreover, substrate mixture experiments show no increased hydrolysis of phosphorus when two substrates are present in the incubation mixture. Increased phosphatase activity toward both glucose 1-phosphate and sodium β-glycerophosphate resulted when corticosteroids were administered in large doses for 72 hours. The data, while not providing absolute proof, are compatible with the hydrolysis of phosphorus at pH 9.9, being due in the case of all three substrates to the activity of the same phosphomonoesterase or group of phosphomonesterases. At pH 5.5, phosphatase activity toward both sodium β-glycerophosphate and adenosine 5'-phosphate was likewise demonstrated, but, in leukocytes, the pH of maximal activity varies from subject to subject and is dependent to a large extent on the amount of the highly variable "alkaline phosphatase" activity present in any given cell population at the time of analysis.

Inhibition by concanavalin A as the basis for a specific assay of serum 5'-nucleotidase activity.

1977 ◽  
Vol 23 (12) ◽  
pp. 2311-2323 ◽  
Author(s):  
E R Zygowicz ◽  
F W Sunderman ◽  
E Horak ◽  
J F Dooley
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Concanavalin A ◽  
Significant Inhibition ◽  
Nucleotidase Activity ◽  
Hepatocellular Injury ◽  
Duct Ligation ◽  
The Difference ◽  
Hydrolysis Of

Abstract Concanavalin A inhibits serum 5'-nucleotidase activity, without causing significant inhibition of alkaline phosphatase activity. This observation serves as the basis for a new method for assaying the 5'-nucleotidase activity in serum, which depends upon the difference between the enzymic hydrolysis of adenosine-5'-monophosphate in the presence and absence of concanavalin A. A denosine released by the 5'-nucleotidase reaction is deaminated by a coupled reaction with adenosine deaminase to liberate inosine and ammonia, and ammonia is measured colorimetrically by the Berthelot reaction. In sera from 40 healthy adult persons, 5'-nucleotidase activity averaged 6.4 U/liter (SD, +/-2.0; range, 3-12). In sera from 100 patients, measurements of 5'-nucleotidase activity by the new assay averaged 8% lower than by a generally accepted method in which phenyl phosphate is used to suppress hydrolysis of adenosine-5'-monophosphate by alkaline phosphatase activity. The clinical validy of the new assay was tested by measuring serum 5'-nucleotidase activities in rats with bile duct ligation and in rats treated with thioacetamide to induce hepatocellular injury.

scholarly journals Potential inhibitors of rat tooth alkaline phosphatase studied by means of different histochemical techniques.

1979 ◽  
Vol 27 (5) ◽  
pp. 982-988 ◽  
Author(s):  
A Larsson ◽  
G Hasselgren
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Sodium Fluoride ◽  
Alkaline Phosphatase Activity ◽  
Staining Pattern ◽  
Alkaline Phosphatases ◽  
Phosphate Ion ◽  
Potential Inhibitors ◽  
Lead Pyrophosphate ◽  
Hydrolysis Of

Two histochemical methods for demonstration of alkaline phosphatase activity, a lead pyrophosphate- anda naphtholphosphate technique, were compared. Since different results may be due to methodological differences as well as different enzyme activities, the enzymatic hydrolysis of the naphtholphosphate was visualized both by means of an azo-dye coupler and by lead-capturing of the liberated phosphate ion. Various potential inhibitors of alkaline phosphatase activity (diphosphonate, D-penicillamine, and sodium fluoride) were also tested. The use of diphosphonate and D-penicillamine resulted in inhibited or reduced staining, which could mainly be explained by an interference by these compounds with components in the incubation media rather than with the enzyme itself. The addition of sodium fluoride had no effect on the naphtholphosphate staining pattern irrespective of capturing method, whereas the odontoblastic pyrophosphate splitting alkaline phosphatase appeared to be sensitive to sodium fluoride, suggesting the presence of two alkaline phosphatases in odontoblasts.

scholarly journals Toxic benthic cyanobacteria (Microcoleus autumnalis): Genetic structure and ecological effects

2021 ◽  
Author(s):  
◽  
Laura Kelly
Keyword(s):  
Alkaline Phosphatase ◽  
New Zealand ◽  
Phosphatase Activity ◽  
Quantitative Pcr ◽  
Alkaline Phosphatase Activity ◽  
Environmental Samples ◽  
Organic Phosphorus ◽  
Pcr Assay ◽  
Knowledge Gaps ◽  
Quantitative Pcr Assay

<p>Toxic, benthic cyanobacterial proliferations occur in rivers globally and are increasing in both frequency and severity. More than 100 dog deaths have been reported in New Zealand since 2005, and dogs have died due to cyanotoxins from benthic cyanobacteria in California and France in recent years. In New Zealand, toxic, benthic proliferations are typically dominated by the genus Microcoleus, which produces the potent neurotoxins called anatoxins. Investigations of the drivers of Microcoleus proliferations have been carried out, revealing important relationships between growth, nutrients and flow. Despite increased attention over the past 15 years, significant knowledge gaps remain regarding regulation of anatoxin concentrations in mats and the ecological impacts of toxic Microcoleus-dominated proliferations in aquatic ecosystems. In this study, I aimed to address these crucial knowledge gaps.  Concentrations of anatoxins in Microcoleus-dominated mats are highly variable, ranging from 0 μg g⁻¹ to over 2000 μg g⁻¹ dry weight. Like other cyanobacteria, both toxic and non-toxic strains coexist, and it is possible that the relative abundance of these strains is related to the observed variability in anatoxin concentrations. I developed a quantitative PCR assay specific to the Microcoleus anaC gene and combined this with a 16S rRNA quantitative PCR specific to cyanobacteria. This assay enabled the relative abundance of toxic and non-toxic strains to be quantified for the first time in environmental samples of Microcoleus-dominated mats. The quantitative PCR assay was applied to 122 environmental samples. Toxic cells made up 0% to 30.3% of the samples and significant differences were detectable among rivers, with wide variation evident both within and among rivers. Anatoxin contents in samples were significantly correlated with the proportion of toxic cells, suggesting that variation in anatoxin concentrations are related primarily to the dominance of toxic strains.   A field study was conducted in California to identify cyanotoxin producers, investigate the utility of the primers from the quantitative PCR developed in the previous chapter in an international setting and determine the extent of spatial variability in anatoxin concentrations and quotas. Samples were collected from the Eel and Russian rivers in northern California and gene screening, followed by sequencing, was conducted to identify likely cyanotoxin producers. Cyanotoxin concentrations were measured using liquid chromatography tandem-mass spectrometry and the anatoxin quotas were determined using droplet digital PCR. Cyanotoxin producers were identified as Microcoleus producing anatoxins and Nodularia producing nodularin. Anatoxin concentrations were highly variable and differed significantly among sites; however, this variability did not extend to anatoxin quotas, indicating that the abundance of toxic cells also drives anatoxin content in this system. The anatoxin congener dihydroanatoxin-a comprised a significant proportion of the total anatoxins (38%–71%), indicating that this congener should be included in monitoring. Mats dominated by the green alga Cladophora glomerata contained both anatoxins and nodularin; thus, they may pose an exposure risk to cyanotoxins.  Microcoleus-dominated mats grow in waters with moderate concentrations of dissolved inorganic nitrogen and low concentrations of dissolved reactive phosphorus. Acquisition of phosphorus from organic sources, in addition to within-mat nutrient cycling, may explain how Microcoleus can obtain high biomass in low nutrient environments. In chapter 4, I compare the alkaline phosphatase activity of four toxic and four non-toxic strains under four phosphorus regimes to identify the potential for Microcoleus to use organic phosphorus as a nutrient source. Toxic strains exhibited greater alkaline phosphatase activity than non-toxic strains; however, considerable variability was evident among strains with the same toxigenicity. Environmental mat samples were collected from sites on an upstream-downstream gradient and across a diel cycle, and alkaline phosphatase activity measured. There was a significant difference in alkaline phosphatase activity between the most upstream and downstream site. No diel changes in alkaline phosphatase activity were apparent. The presence of alkaline phosphatase activity suggests that organic phosphorus sources may be accessible to Microcoleus.   To date, management of, and research on, toxic, benthic cyanobacterial proliferations has been focused largely on identifying drivers of growth and toxin production. As a result, there is a significant lack of information on the effects of Microcoleus-dominated proliferations on the wider ecosystem. In chapter 5, an ecotoxicological study was undertaken on Deleatidium spp. larvae using purified anatoxins to address this knowledge gap. Deleatidium spp. larvae were exposed to a range of doses of anatoxin-a, dihydroanatoxin-a, or a mixture of homoanatoxin-a and dihydrohomoanatoxin-a. No significant mortality was observed for any dose or toxin congener. Larvae exposed to high doses (300 μg L⁻¹ to 600 μg L⁻¹) of dihydroanatoxin-a had measurable concentrations of the toxin in their tissues 24-hours post-exposure. The lack of mortality observed, combined with detectable anatoxins in tissues post-exposure, is indicative of a potential pathway for anatoxin transfer or bioaccumulation, and warrants further investigation.  Overall, this thesis has addressed a number of critical knowledge gaps in our understanding of Microcoleus. Continued effort is needed to broaden our understanding of the physiological and ecological role of anatoxins to improve risk assessments and ultimately inform better management of Microcoleus proliferations.</p>

scholarly journals Toxic benthic cyanobacteria (Microcoleus autumnalis): Genetic structure and ecological effects

2021 ◽  
Author(s):  
◽  
Laura Kelly
Keyword(s):  
Alkaline Phosphatase ◽  
New Zealand ◽  
Phosphatase Activity ◽  
Quantitative Pcr ◽  
Alkaline Phosphatase Activity ◽  
Environmental Samples ◽  
Organic Phosphorus ◽  
Pcr Assay ◽  
Knowledge Gaps ◽  
Quantitative Pcr Assay

<p>Toxic, benthic cyanobacterial proliferations occur in rivers globally and are increasing in both frequency and severity. More than 100 dog deaths have been reported in New Zealand since 2005, and dogs have died due to cyanotoxins from benthic cyanobacteria in California and France in recent years. In New Zealand, toxic, benthic proliferations are typically dominated by the genus Microcoleus, which produces the potent neurotoxins called anatoxins. Investigations of the drivers of Microcoleus proliferations have been carried out, revealing important relationships between growth, nutrients and flow. Despite increased attention over the past 15 years, significant knowledge gaps remain regarding regulation of anatoxin concentrations in mats and the ecological impacts of toxic Microcoleus-dominated proliferations in aquatic ecosystems. In this study, I aimed to address these crucial knowledge gaps.  Concentrations of anatoxins in Microcoleus-dominated mats are highly variable, ranging from 0 μg g⁻¹ to over 2000 μg g⁻¹ dry weight. Like other cyanobacteria, both toxic and non-toxic strains coexist, and it is possible that the relative abundance of these strains is related to the observed variability in anatoxin concentrations. I developed a quantitative PCR assay specific to the Microcoleus anaC gene and combined this with a 16S rRNA quantitative PCR specific to cyanobacteria. This assay enabled the relative abundance of toxic and non-toxic strains to be quantified for the first time in environmental samples of Microcoleus-dominated mats. The quantitative PCR assay was applied to 122 environmental samples. Toxic cells made up 0% to 30.3% of the samples and significant differences were detectable among rivers, with wide variation evident both within and among rivers. Anatoxin contents in samples were significantly correlated with the proportion of toxic cells, suggesting that variation in anatoxin concentrations are related primarily to the dominance of toxic strains.   A field study was conducted in California to identify cyanotoxin producers, investigate the utility of the primers from the quantitative PCR developed in the previous chapter in an international setting and determine the extent of spatial variability in anatoxin concentrations and quotas. Samples were collected from the Eel and Russian rivers in northern California and gene screening, followed by sequencing, was conducted to identify likely cyanotoxin producers. Cyanotoxin concentrations were measured using liquid chromatography tandem-mass spectrometry and the anatoxin quotas were determined using droplet digital PCR. Cyanotoxin producers were identified as Microcoleus producing anatoxins and Nodularia producing nodularin. Anatoxin concentrations were highly variable and differed significantly among sites; however, this variability did not extend to anatoxin quotas, indicating that the abundance of toxic cells also drives anatoxin content in this system. The anatoxin congener dihydroanatoxin-a comprised a significant proportion of the total anatoxins (38%–71%), indicating that this congener should be included in monitoring. Mats dominated by the green alga Cladophora glomerata contained both anatoxins and nodularin; thus, they may pose an exposure risk to cyanotoxins.  Microcoleus-dominated mats grow in waters with moderate concentrations of dissolved inorganic nitrogen and low concentrations of dissolved reactive phosphorus. Acquisition of phosphorus from organic sources, in addition to within-mat nutrient cycling, may explain how Microcoleus can obtain high biomass in low nutrient environments. In chapter 4, I compare the alkaline phosphatase activity of four toxic and four non-toxic strains under four phosphorus regimes to identify the potential for Microcoleus to use organic phosphorus as a nutrient source. Toxic strains exhibited greater alkaline phosphatase activity than non-toxic strains; however, considerable variability was evident among strains with the same toxigenicity. Environmental mat samples were collected from sites on an upstream-downstream gradient and across a diel cycle, and alkaline phosphatase activity measured. There was a significant difference in alkaline phosphatase activity between the most upstream and downstream site. No diel changes in alkaline phosphatase activity were apparent. The presence of alkaline phosphatase activity suggests that organic phosphorus sources may be accessible to Microcoleus.   To date, management of, and research on, toxic, benthic cyanobacterial proliferations has been focused largely on identifying drivers of growth and toxin production. As a result, there is a significant lack of information on the effects of Microcoleus-dominated proliferations on the wider ecosystem. In chapter 5, an ecotoxicological study was undertaken on Deleatidium spp. larvae using purified anatoxins to address this knowledge gap. Deleatidium spp. larvae were exposed to a range of doses of anatoxin-a, dihydroanatoxin-a, or a mixture of homoanatoxin-a and dihydrohomoanatoxin-a. No significant mortality was observed for any dose or toxin congener. Larvae exposed to high doses (300 μg L⁻¹ to 600 μg L⁻¹) of dihydroanatoxin-a had measurable concentrations of the toxin in their tissues 24-hours post-exposure. The lack of mortality observed, combined with detectable anatoxins in tissues post-exposure, is indicative of a potential pathway for anatoxin transfer or bioaccumulation, and warrants further investigation.  Overall, this thesis has addressed a number of critical knowledge gaps in our understanding of Microcoleus. Continued effort is needed to broaden our understanding of the physiological and ecological role of anatoxins to improve risk assessments and ultimately inform better management of Microcoleus proliferations.</p>

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