Replacement of potassium ions by ammonium ions in different micro-organisms grown in potassium-limited chemostat culture

1989 ◽  
Vol 152 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Edward T. Buurman ◽  
Jill Pennock ◽  
David W. Tempest ◽  
M. Joost Teixeira de Mattos ◽  
Oense M. Neijssel
Keyword(s):  
Chemostat Culture ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
Micro Organisms

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

Kinetics and Reaction Mechanism of the Carbamylphosphate Synthetase of a Multienzyme Aggregate from Yeast

1975 ◽  
Vol 53 (6) ◽  
pp. 721-730 ◽  
Author(s):  
David M. Aitken ◽  
Peter F. Lue ◽  
J. Gordin Kaplan
Keyword(s):  
Reaction Mechanism ◽  
Feedback Inhibition ◽  
Enzyme Reaction ◽  
Competitive Inhibitor ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
Nitrogen Donor ◽  
Sequential Addition ◽  
A Site ◽  
Carbamylphosphate Synthetase

We have studied the kinetics and reaction mechanism of the carbamylphosphate synthetase of an enzyme aggregate functioning in the pyrimidine pathway of yeast. Mg–ATP was found to be one of the substrates of the enzyme reaction which was activated by free Mg2+ and inhibited by free ATP. Feedback inhibition by UTP was non-competitive with respect to both glutamine and bicarbonate. Potassium ions were essential for activity and could not be replaced by sodium. Glutamine could be replaced partially by ammonium ions as nitrogen donor. A bicarbonate-dependent cleavage of ATP was shown to take place in the absence of L-glutamine; L-glutamate was a competitive inhibitor of L-glutamine and the enzyme was shown to synthesize ATP when incubated with ADP and carbamyl phosphate. The reaction mechanism was found to involve sequential addition of the substrates bicarbonate and Mg–ATP and release of ADP, followed by addition of the third substrate glutamine. The purine nucleotide XMP had a pronounced activating effect on the enzyme, acting at a site different from that of UTP. Saturating levels of Mg–ATP eliminated this activation.

ALDOSTERONE STIMULATION IN VITRO

1966 ◽  
Vol 52 (4) ◽  
pp. 515-526 ◽  
Author(s):  
Jürg Müller
Keyword(s):  
Angiotensin Ii ◽  
Isotope Dilution ◽  
Total Radioactivity ◽  
Potassium Ions ◽  
Total Production ◽  
Monovalent Cations ◽  
Ammonium Ions ◽  
Double Isotope ◽  
Radioactive Substrate

ABSTRACT Tritiated precursors of corticosteroids were incubated with rat adrenal sections. At the end of the incubation, tritium-labelled aldosterone and corticosterone were determined by double isotope dilution procedures. When corticosterone-[3H], deoxycorticosterone-[3H], progesterone-[3H] or pregnenolone-[3H] were used as substrates, 2–5% of the total radioactivity in the incubation medium could be recovered in the aldosterone fraction, while 20–25% of the latter three substrates were incorporated into corticosterone. Potassium ions, ammonium ions, angiotensin II and ACTH markedly stimulated the biosynthesis of unlabelled aldosterone from endogenous precursors. However, they did not influence the amounts of radioactive substrate converted to aldosterone or corticosterone. NADP and glucose 6-phosphate stimulated both the total production of aldosterone and corticosterone and the conversion of deoxycorticosterone-[3H] and of pregnenolone-[3H] to corticosterone. Only minute amounts of tritiated cholesterol were converted to corticosteroids. Angiotensin II and ammonium ions significantly stimulated the conversion of cholesterol-[3H] to aldosterone, while ACTH, potassium ions and particularly NADP and glucose 6-phosphate enhanced its incorporation into both aldosterone and corticosterone. These findings indicate that, like ACTH and NADPH2, monovalent cations and angiotensin act mainly on the conversion of cholesterol to pregnenolone and do not directly stimulate hydroxylation or dehydrogenation in position 18.

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

scholarly journals Modulation of the intestinal microbiota and the metabolites produced by the administration of ice cream and a dietary supplement containing the same probiotics

2020 ◽  
Vol 124 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Vivian Cristina da Cruz Rodrigues ◽  
Ana Luiza Rocha Faria Duque ◽  
Luciana de Carvalho Fino ◽  
Fernando Moreira Simabuco ◽  
Adilson Sartoratto ◽  
...  
Keyword(s):  
Dietary Supplement ◽  
Intestinal Microbiota ◽  
Ice Cream ◽  
Ammonium Ions ◽  
Real Time Quantitative Pcr ◽  
Bifidobacterium Animalis ◽  
Qrt Pcr ◽  
Micro Organisms ◽  
Microbiota Diversity ◽  
Generation Sequencing

AbstractThe aim of the present work was to compare the capacity to modulate the intestinal microbiota and the production of metabolites after 14 d administration of a commercial dietary supplement and a manufactured ice cream, both containing the same quantity of inulin and the same viable counts of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis BB-12, using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model. Samples of the colonic contents were evaluated microbiologically by real-time quantitative PCR (qRT-PCR) and next-generation sequencing and chemically by the production of SCFA (acetate, propionate and butyrate) and ammonium ions ($\text{NH}_4^ + $). Statistical analyses were carried out for all the variables using the two-way ANOVA followed by the Tukey multiple comparisons test (P < 0·05) for metabolite production, qRT-PCR and the bioinformatics analysis for microbiota diversity. Dietary supplement and ice cream were able to deliver the probiotic L. acidophilus and B. animalis to the simulated colon and modulate the microbiota, increasing beneficial micro-organisms such as Bifidobacterium spp., Bacteroides spp. and Faecalibacterium spp. for dietary supplement administration, and Lactobacillus spp. for ice cream supplementation. However, the ice cream matrix was probably more favourable for the maintenance of the metabolic activity of the probiotics in the SHIME® model, due to the larger amounts of acetate, propionate, butyrate and ammonium ions obtained after 14 d of supplementation. In conclusion, both ways of probiotic supplementation could be efficient, each with its own particularities.

scholarly journals Replacement of potassium ions by ammonium ions in potassium-limited chemostat cultures of Candida utilis NCYC 321

1993 ◽  
Vol 107 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Ed T. Buurman ◽  
Paul T.D. Herman ◽  
M. Joost Teixeira de Mattos ◽  
Oense M. Neijssel
Keyword(s):  
Candida Utilis ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
Chemostat Cultures

scholarly journals Evolution of cation binding in the active sites of P-loop nucleoside triphosphatases

2018 ◽  
Author(s):  
Daria N. Shalaeva ◽  
Dmitry A. Cherepanov ◽  
Michael Y. Galperin ◽  
Armen Y. Mulkidjanian
Keyword(s):  
Active Sites ◽  
Atp Hydrolysis ◽  
Md Simulations ◽  
Cation Binding ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Ammonium Ions ◽  
Phosphate Chain ◽  
Comparative Structure ◽  
Phosphate Groups

AbstractThe activity of cellular nucleoside triphosphatases (NTPases) must be tightly controlled to prevent spontaneous ATP hydrolysis leading to cell death. While most P-loop NTPases require activation by arginine or lysine fingers, some of the apparently ancestral ones are, instead, activated by potassium ions, but not by sodium ions. We combined comparative structure analysis of P-loop NTPases of various classes with molecular dynamics (MD) simulations of Mg-ATP complexes in water and in the presence of potassium, sodium, or ammonium ions. In all analyzed structures, the conserved P-loop motif keeps the triphosphate chains of enzyme-bound NTPs in an extended, catalytically prone conformation, similar to that attained by ATP in water in the presence of potassium or ammonium ions bound between alpha- and gamma-phosphate groups. The smaller sodium ions could not reach both alpha- and gamma-phosphates of a protein-bound extended phosphate chain and therefore are unable to activate most potassium-dependent P-loop NTPases.

scholarly journals Evolution of cation binding in the active sites of P-loop nucleoside triphosphatases in relation to the basic catalytic mechanism

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Daria N Shalaeva ◽  
Dmitry A Cherepanov ◽  
Michael Y Galperin ◽  
Andrey V Golovin ◽  
Armen Y Mulkidjanian
Keyword(s):  
Active Sites ◽  
Catalytic Mechanism ◽  
Md Simulations ◽  
Basic Mechanism ◽  
Cation Binding ◽  
Activation Mechanism ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
Mechanism Of Hydrolysis ◽  
Comparative Structure

The ubiquitous P-loop fold nucleoside triphosphatases (NTPases) are typically activated by an arginine or lysine ‘finger’. Some of the apparently ancestral NTPases are, instead, activated by potassium ions. To clarify the activation mechanism, we combined comparative structure analysis with molecular dynamics (MD) simulations of Mg-ATP and Mg-GTP complexes in water and in the presence of potassium, sodium, or ammonium ions. In all analyzed structures of diverse P-loop NTPases, the conserved P-loop motif keeps the triphosphate chain of bound NTPs (or their analogs) in an extended, catalytically prone conformation, similar to that imposed on NTPs in water by potassium or ammonium ions. MD simulations of potassium-dependent GTPase MnmE showed that linking of alpha- and gamma phosphates by the activating potassium ion led to the rotation of the gamma-phosphate group yielding an almost eclipsed, catalytically productive conformation of the triphosphate chain, which could represent the basic mechanism of hydrolysis by P-loop NTPases.

scholarly journals Nitrogen-limited behaviour of micro-organisms growing in the presence of large concentrations of ammonium ions

1989 ◽  
Vol 58 (2-3) ◽  
pp. 229-232 ◽  
Author(s):  
Ed T. Buurman ◽  
M.Joost Teixeira Mattos ◽  
Oense M. Neijssel
Keyword(s):  
Ammonium Ions ◽  
Micro Organisms

New Enzymatic Method with Tryptophanase for Determining Potassium in Serum

1992 ◽  
Vol 38 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Shigeki Kimura ◽  
Seishi Asari ◽  
Sadao Hayashi ◽  
Yoshihisa Yamaguchi ◽  
Ryo Fushimi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enzymatic Reaction ◽  
Potassium Ion ◽  
Ammonium Ion ◽  
Potassium Ions ◽  
Enzymatic Method ◽  
Ammonium Ions ◽  
E Coli ◽  
Ion Concentrations ◽  
Standard Curve

Abstract We established a simple and rapid enzymatic method for measuring potassium ion in serum by using tryptophanase (EC 4.1.99.1) purified from Escherichia coli K12 strain (E. coli K12 IFO 3301). The presence of pyridoxal 5-phosphate promotes this enzymatic reaction, and potassium and (or) ammonium ions further accelerate it, with ammonium and potassium ions providing equivalent acceleration. We eliminated endogenous ammonium ion by using glutamate dehydrogenase (GLDH; EC 1.4.1.4), then produced ammonium ion in the presence of tryptophanase, tryptophan, and pyridoxal 5-phosphate. The concentration of formed ammonium ion, which was proportional to that of potassium ion in sample, was determined by adding GLDH to produce NADP+ in the presence of 2-oxoglutarate and NADPH; we then read the change of absorbance at 340 nm. The standard curve was linear for potassium ion concentrations up to 7.00 mmol/L. The within-assay variation (CV) was 0.89% at 5.51 mmol/L and 1.32% at 3.37 mmol/L. The day-to-day CVs were 0.99% at 6.85 mmol/L and 1.71% at 3.52 mmol/L. Analytical recoveries ranged from 98.7% to 108.9%. The correlation coefficient between values obtained with this enzymatic assay (y) and by flame photometry (x) was 0.995: y = 0.984x + 0.091 mmol/L (Sy.x = 0.105, n = 100). The presence of hemoglobin, bilirubin, or other cations little affects this system.

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