Epilimnetic Phosphorus Cycling: Influence of Humic Materials and Iron on Coexisting Major Mechanisms

1986 ◽  
Vol 43 (2) ◽  
pp. 302-310 ◽  
Author(s):  
David A. Francko
Keyword(s):  
Alkaline Phosphatase ◽  
Lake Water ◽  
Ferric Iron ◽  
P Uptake ◽  
Humic Material ◽  
Low Concentrations ◽  
Uptake Rates ◽  
Humic Materials ◽  
The Continuum ◽  
Fe Addition

Two major orthophosphate recycling mechanisms, alkaline phosphatase activity and the photodependent release of P from UV-sensitive complex P, cooccurred in epilimnetic samples from four trophically dissimilar lakes in northcentral Oklahoma. Both of these processes were strongly perturbed upon addition of low concentrations of dissolved humic material (DHM) and ferric iron, alone or in concert, to lake water samples. Planktonic orthophosphate uptake rates were also significantly altered by DHM/Fe addition, and, although the majority of P-uptake was accomplished by cells <3.0 μm in diameter, the effects of DHM/Fe were not size-selective. Additions of DHM/Fe to lake water appeared to promote elevated concentrations of orthophosphate and phosphomonoester substrates of alkaline phosphatase in lake water filtrates. Collectively, these data suggest that epilimnetic P cycling may be viewed as a continuum of processes and that the position of a given lake in the continuum is dynamic and influenced by DHM and Fe.

scholarly journals Perbaikan Sifat Kimia Oxisol dengan Pemberian Bahan Humat dan Pupuk P untuk Meningkatkan Serapan Hara dan Produksi Tanaman Jagung (Zea mays, L.)

Jurnal Solum ◽  
2012 ◽  
Vol 9 (2) ◽  
pp. 51
Author(s):  
Herviyanti Herviyanti ◽  
Chici Anche ◽  
Gusnidar Gusnidar ◽  
Irwan Darfis
Keyword(s):  
Nutrient Uptake ◽  
Chemical Properties ◽  
P Uptake ◽  
P Availability ◽  
Humic Material ◽  
Corn Production ◽  
Soil P ◽  
Randomized Design ◽  
Humic Materials ◽  
P Fertilizer

A research was carried out at glass house and at Soil Laboratory of Faculty of Agriculture, Andalas University Padang. The experiment was aimed to determine the interaction between humic material from compost and P fertilizer on some chemical properties of Oxisol, nutrient uptake and corn production. This experiment consisted of 2 factors (4 x 4) with three replications which were allocated in completely randomized design (CRD). The first factor was humic material having 4 doses (0, 400, 800, and 1200 ppm) and the 2nd factor was P fertilizer having 4 doses (100%, 75%, 50%, and 25% of recomendation (R)). The result showed that there was : 1) Interaction between humic materials and P fertilizer for the quality the corn seeds. Application of 800 ppm humic material improved the quality of the seeds even though at low level of P fertilizer. 2) Then, it also increased availability of P by 23.03 ppm, N total by 0.09 %, and decreased Al-exch by 0.53 me (100 g)-1 and Fe-exch by 25.62 ppm compared to threatment without application of humic material. Likewise, nutrients (N and P) uptake by plant also increased by 0.28 and 0.03 %, respectively. 3) Application of P fertilizer at 75 % R increased soil P availability by 3.77 ppm, N and P content of plant by 0.43 % and 0.06 %, and seed weight by 13.20 g and decreased Fe-exch by 21.16 ppm, compared to 25 % R of P fertilizer.Keywords : humic material, P- fertilizer, nutrient uptake

Toxicity of anionic and cationic surfactant to Acinetobacter junii in pure culture

2007 ◽  
Vol 2 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Jasna Hrenovic ◽  
Tomislav Ivankovic
Keyword(s):  
Activated Sludge ◽  
Pure Culture ◽  
Sodium Dodecyl ◽  
P Uptake ◽  
Hexadecyltrimethylammonium Bromide ◽  
Negative Effects ◽  
Acinetobacter Junii ◽  
Uptake Rates ◽  
Eukaryotic Organisms ◽  
P Uptake Rates

AbstractThe harmful effects of surfactants to the environment are well known. We were interested in investigating their potential toxicity in a pure culture of Acinetobacter junii, a phosphate (P)-accumulating bacterium. Results showed a high acute toxicity of sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HDTMA) against A. junii. The estimated EC50 values of the HDTMA for the inhibition of CFUs in the pure culture of A. junii was 3.27 ± 1.12 × 10−7 mol L−1 and for the inhibition of the P-uptake rates 2.47 ± 0.51 × 10−6 mol L−1. For SDS, estimated EC50 values for the inhibition of CFUs in the pure culture of A. junii was 5.00 ± 2.95 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 3.33 ± 0.96 × 10−4 mol L−1. The obtained EC50 values in the standardised yeast toxicity test using Saccharomyces cerevisiae were 3.03 ± 0.38 × 10−4 and 4.33 ± 0.32 × 10−5 mol L−1 for SDS and HDTMA, respectively. These results emphasized the need to control concentrations of surfactants entering the activated sludge system. The negative effects of these toxicants could greatly decrease populations of P-accumulating bacteria, as well as eukaryotic organisms, inhabiting activated sludge systems, which in turn could result in the decrease of the system efficiency.

Anion-stimulated ATPase activity of brush border from rat small intestine.

1979 ◽  
Vol 236 (1) ◽  
pp. E70 ◽  
Author(s):  
M H Humphreys ◽  
L Y Chou
Keyword(s):  
Alkaline Phosphatase ◽  
Atpase Activity ◽  
Brush Border ◽  
Atp Hydrolysis ◽  
Intestinal Transport ◽  
Mitochondrial Enzymes ◽  
Intestinal Alkaline Phosphatase ◽  
Ph Optimum ◽  
Low Concentrations ◽  
Small Intestinal

Differential centrifugation of rat small intestinal homogenates produced a crude brush border (BB) fraction that was enriched 15-fold for the marker enzymes, alkaline phosphatase and sucrase; contamination with mitochondrial enzymes, monoamine oxidase and succinate dehydrogenase, was minimal. ATP hydrolysis by this BB fraction was stimulated by addition of several anions to the incubation medium: HCO3 and Cl were equally effective in this regard, with NO3, NO2, SO4, and acetate being less stimulatory. SCN and CNO inhibited ATPase activity, whereas the divalent anion SO3 was stimulatory at low concentrations (less than 25 mM) but inhibitory at 100 mM. Maximum anion stimulation was observed at a Mg concentration of 0.5 mM, and pH optimum was 8.5. Kinetic analysis showed that HCO3 increased the Vmax without altering the Km for ATP; the Ka for this effect of HCO3 was 35 mM. This enzyme activity was completely inhibited by 20 mM L-phenylalanine, 10 mM L-cysteine, and 3 mM EDTA, compounds that also inhibited intestinal alkaline phosphatase. These results demonstrate the presence of anion-stimulated ATPase activity in rat small intestinal brush border and suggest that this activity may be related to intestinal alkaline phosphatase. The role of this enzyme in intestinal transport is not known, but could relate to the regulation of intestinal absorption and secretion.

Phosphorus release and uptake during start-up of a covered and non-aerated sequencing batch reactor with separate feeding of VFA and sulfate

2012 ◽  
Vol 65 (5) ◽  
pp. 840-844 ◽  
Author(s):  
D. Wu ◽  
T. Hao ◽  
H. Lu ◽  
H. K. Chui ◽  
M. C. M. van Loosdrecht ◽  
...  
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
P Uptake ◽  
Sulfur Cycle ◽  
Biological Phosphorus Removal ◽  
P Release ◽  
Start Up ◽  
Uptake Rates ◽  
Biological Phosphorus ◽  
P Removal

This study explored a sulfur cycle-associated biological phosphorus (P) removal process in a covered and non-aerated sequencing batch reactor (SBR) fed with volatile fatty acid (VFA) and sulfate separately. During the 60-day start-up, both phosphate release and uptake rates increased, while poly-phosphate cyclically increased and decreased accordingly. The P-release and P-uptake rates were associated with VFA uptake and sulfate reduction. The average ratio of potassium to phosphate during the P-uptake and P-release was also determined to be 0.29–0.31 mol K/mol P, which is close to a reported value (0.33) for biological phosphorus removal. All this evidence confirmed there was biological P removal in this reactor, in which metabolism could be different from conventional biological P removal.

Phosphorus Kinetics in Lake Superior: Light Intensity and Phosphate Uptake in Algae

1981 ◽  
Vol 38 (2) ◽  
pp. 224-232 ◽  
Author(s):  
C. Nalewajko ◽  
K. Lee ◽  
H. Shear
Keyword(s):  
Management Strategy ◽  
Phosphorus Content ◽  
Lake Superior ◽  
Chlorella Pyrenoidosa ◽  
Phosphorus Limitation ◽  
P Uptake ◽  
Uptake Kinetics ◽  
Low Light ◽  
Light Levels ◽  
Uptake Rates

Epilimnetic phytoplankton in Lake Superior in September, 1979, had low Ik values (75–190 μE∙m−2∙s−1), low N/P ratios (8 to 13:1) and 32PO4–P uptake kinetics that were not consistent with a state of extreme phosphorus limitation. Parallel laboratory experiments with Chlorella pyrenoidosa indicated that phosphorus content per cell was higher and uptake rates of phosphate were lower in cells grown under low light (57 μE∙m−2∙s−1) than those under high light (340 μE∙m−2∙s−1). Maximum 32PO4 uptake occurred at about 50–60 μE∙m−2∙s−1 in both cultures indicating 32PO4 uptake kinetics are light dependent at very low light levels, below or close to their Ik values. It appears that light and not phosphorus limited phytoplankton growth in Lake Superior at the time of our experiments. Antecedent solar radiation prior to our experiments coupled with complete mixing of the top 20–25 m of the Lake possibly resulted in a low light-adapted phytoplankton population. We suggest that phosphorus control need not be the correct management strategy to maintain oligotrophy in Lake Superior. Key words: phosphorus, kinetics, light, primary production, mixing, management

scholarly journals ETB receptor activation leads to activation and phosphorylation of NHE3

1999 ◽  
Vol 276 (4) ◽  
pp. C938-C945 ◽  
Author(s):  
Y. Peng ◽  
O. W. Moe ◽  
T.-S. Chu ◽  
P. A. Preisig ◽  
M. Yanagisawa ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Tyrosine Phosphorylation ◽  
Time Course ◽  
Receptor Activation ◽  
Endothelin Receptors ◽  
Receptor Specificity ◽  
Low Concentrations ◽  
Sds Page ◽  
Etb Receptor ◽  
In Cells

In OKP cells expressing ETB endothelin receptors, activation of Na+/H+antiporter activity by endothelin-1 (ET-1) was resistant to low concentrations of ethylisopropyl amiloride, indicating regulation of Na+/H+exchanger isoform 3 (NHE3). ET-1 increased NHE3 phosphorylation in cells expressing ETB receptors but not in cells expressing ETAreceptors. Receptor specificity was not due to demonstrable differences in receptor-specific activation of tyrosine phosphorylation pathways or inhibition of adenylyl cyclase. Phosphorylation was associated with a decrease in mobility on SDS-PAGE, which was reversed by treating immunoprecipitated NHE3 with alkaline phosphatase. Phosphorylation was first seen at 5 min and was maximal at 15–30 min. Phosphorylation was maximal with 10−9 M ET-1. Phosphorylation occurred on threonine and serine residues at multiple sites. In summary, ET-1 induces NHE3 phosphorylation in OKP cells on multiple threonine and serine residues. ETB receptor specificity, time course, and concentration dependence are all similar between ET-1-induced increases in NHE3 activity and phosphorylation, suggesting that phosphorylation plays a key role in activation.

scholarly journals Uptake Rates of Oxygen and Sulfide Measured with Individual Thiomargarita namibiensis Cells by Using Microelectrodes

2002 ◽  
Vol 68 (11) ◽  
pp. 5746-5749 ◽  
Author(s):  
Heide N. Schulz ◽  
Dirk de Beer
Keyword(s):  
Low Concentrations ◽  
Uptake Rates

ABSTRACT Gradients of oxygen and sulfide measured towards individual cells of the large nitrate-storing sulfur bacterium Thiomargarita namibiensis showed that in addition to nitrate oxygen is used for oxidation of sulfide. Stable gradients around the cells were found only if acetate was added to the medium at low concentrations.

Effect of humic-plant feed preparations on biochemical blood parameters of laying hens in deep litter housing system

2015 ◽  
Vol 18 (1) ◽  
pp. 131-139 ◽  
Author(s):  
F. Bubel ◽  
Z. Dobrzański ◽  
A. Gaweł ◽  
K. Pogoda-Sewerniak ◽  
E.R. Grela
Keyword(s):  
Alkaline Phosphatase ◽  
Biochemical Parameters ◽  
Blood Parameters ◽  
Feed Additives ◽  
Housing System ◽  
Serum Total Protein ◽  
Humic Materials ◽  
Limited Degree ◽  
Biochemical Indices ◽  
Food Mixture

AbstractAn influence of various humic-plant feed additives based on some herbs (nettle, chamomile, yarrow, perforatum), lucerne and humic materials on biochemical indices of Lohmann Brown (LB) layers blood plasma was estimated. Hens were housed in deep litter system, 20 birds in a group. Four groups were formed: control (C – standard feeding), and experimental, supplemented with preparations: E-1 herbal-humic, E-2 humic-herbal and E-3 – humic-lucerne. Hens were placed in the pens on the 16thweek of life, addition of preparations with standard food mixture started at the 22ndwk and lasted until 66thwk of life. Blood for analyses was collected four times in the following periods: 27, 37, 54 and 65thwk of life. The applied humic-plant preparations to a limited degree affected the values of examined biochemical parameters in serum: total protein (TP), albumins (Albs), glucose (Glu), urea, triacylglycerols (TAG), total cholesterol (TCh), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP). It is difficult to determine based on these study, which preparation is one the most active biologically, however is seems that humic-lucerne preparation affected the examined blood parameters to the highest degree. The reference values ranges in hens blood serum LB hens were proposed for: TP (43-65 g/l), Albs (15-22 g/l), urea (0.5-1.2 mmol/l), Glu 10-15 mmol/l), TCh (2.2-4.5 mmol/l), TAG (10-24 mmol/l), AST (4-12 U/l), ALT (150-280 mmol/l) and ALP (190-350 U/l).

DETERMINATION OF LOW CONCENTRATIONS OF INORGANIC CARBON IN LAKE WATER

1970 ◽  
Vol 15 (3) ◽  
pp. 481-482 ◽  
Author(s):  
MURRAY G. JOHNSON ◽  
MICHAEL F. P. MICHALSKI
Keyword(s):  
Lake Water ◽  
Inorganic Carbon ◽  
Low Concentrations
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