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1

Plant ureases: roles and regulation

100%
Sirko A., Brodzik R.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 4
Both urea and urease were subjects of early scientific investigations. Urea was the first organic molecule to be synthesized and jack bean urease was the first enzyme ever to be crystallized. About 50 years later it was shown to be the first nickel metalloenzyme. Since then, nickel-dependent ureases have been isolated from many bacteria, fungi and higher plants. They have similar structures and mechanisms of catalysis. A urease apoenzyme needs to be activated. This process requires participation of several accessory proteins that incorporate nickel into the urease forming catalytic site. In this review, ureases from various organisms are briefly described and the similarities of their structures discussed. Moreover, the significance of urea recycling in plants is explained and recent literature data about the function and activation of plant ureases are presented.
2

Urease activity and ATP content in soil and plant related to copper concentration

100%
Snieg B., Nowak J.
Polish Journal of Ecology
|
2005
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tom 53
|
nr 1
This study aimed at the assessment of the influence of various Cu(NO₃)₂ doses added to soil on Cu content in soil and on its influence on the activity of urease and ATP content in soil and in plants of various growth stages. A two-factor pot experiment had been started in 2002 using as test plant – the pea (Pisum sativum L.). Soil was taken from 0–30 cm layer of an arable field (light silt loam, 1.2% C content, and neutral reaction). Four doses of copper (II) nitrate (V) as Cu(NO₃)₂. 3H₂O were applied (each in 4 replications) following: I – control (no salt), II – 0.05 mmol. kg⁻¹soil, III – 0.50 mmol kg⁻¹ and IV – 5.00 mmol. kg⁻¹ soil. According to six degrees classification of soil contamination by copper, application of 0.05 mmol of copper nitrate per kg of soil increased copper content up to high level of natural content in soil (but still 0° of contamination), after application of 0.5 mmol. kg⁻¹ – copper content increased to 1° of contamination, 5.00 mmol kg⁻¹ Cu⁺² dose caused high pollution (4° of contamination). Each pot was filled with 2 kg of the treated soil, and 5 pea seeds were planted per pot. The experiment lasted 56 days. Soil moisture was maintained during the experiment at 60% water holding capacity. In the course of the experiment the following growth stages were noted: 2 pairs of leaves stage (day 14th), flowering stage (day 44th), mature stage (day 56th). At those times soil and plant samples were taken to assess copper content in soil (content of total and 1M HCl soluble Cu), urease activity and ATP levels. A high positive correlation was found between Cu content (total and 1M HCl soluble) in soil and in plants. High Cu content in soil (4° of contamination – high pollution) caused a decrease of urease activity and ATP content in soil. Elevated Cu content in plant caused a distinct inhibition of urease activity in all the analyzed growth stages, and markedly higher content of ATP at the stage of flowering and mature stage of Pisum sativum L.
3

Influence of 2,5-dichloro-1,4-benzoquinone on jack bean urease activity. Inhibitory effect, total reducing capacity and DPPH radical scavenging activity

72%
Kot M., Olech Z.
Acta Biochimica Polonica
|
2011
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tom 58
|
nr 4
Inhibition of jack bean activity by 2,5-dichloro-1,4-benzoquinone (DCBQ) was studied in phosphate buffer, pH 7.0. It was found that DCBQ acted as a strong, time and concentration dependent inactivator of urease. Under the experimental conditions obeyed the terms of pseudo-first-order reaction, urease was totally inactivated. Application of Wilson-Kitz method proved that the urease-DCBQ interaction followed a simple bimolecular process and the presence of intermediate complex was undetectable. The determined second order rate constant of the inactivation was 0.053 (μM min)-1. Thiols such as l-cysteine, glutathione and dithiothreitol (DTT) protected urease from inhibition by DCBQ but DCBQ-modified urease did not regain its activity after DTT application. The thiol protective studies indicated an essential role of urease thiol(s) in the inhibition. The irreversibility of the inactivation showed that the process was a result of a direct modification of urease thiol(s) by DCBQ (DCBQ chlorine(s) substitution). The decomposition of DCBQ in aqueous solution at natural light exposure was monitored by visible spectrophotometry, determination of the total reducing capacity (Folin-Ciocalteu method) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability. The DCBQ conversion resulted in a decrease of the inhibition power and was well correlated with the increase of the total reducing capacity and DPPH scavenging ability. These findings were attributed to DCBQ transformation by photolysis and the hydrolysis effect was found to be negligible.
4

Evaluation of urease activity by the human Ureaplasma species

72%
Biernat-Sudolska M., Bilska-Wilkosz A., Rojek-Zakrzewska D., Zawilinska B., Kosz-Vnenchak M.
Folia Biologica
|
2017
|
tom 65
|
nr 3
5
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Effects of heavy metals on the activity of dehydrogenases, phosphatases and urease in naturally and artificially contaminated soils

72%
Wiatrowska K., Komisarek J., Dluzewski P.
Journal of Elementology
|
2015
|
tom 20
|
nr 3
Most of the processes occurring in soil are catalysed by enzymes. As a result of their sensitivity towards heavy metals, enzymes in contaminated soils are usually less active. The purpose of this paper was to assess the influence of bioavailable forms of Cd, Cu, Pb and Zn on the activity of dehydrogenases, urease, acid and alkaline phosphatase, and to compare the results obtained from naturally and artificially contaminated soils. A pot experiment was carried out on two loamy sand soils, naturally and artificially contaminated with Cd, Cu, Pb and Zn. The total content of heavy metals classified these soils as very heavily contaminated with Cu, heavily contaminated with Pb and contaminated with Cd and Zn, all according to the IUNG system (1995). One of the following organic materials: swine manure or triticale straw, was added to the soil batches. The experiment was carried out in three replications, in two pH ranges: slightly acid and acid. Soil samples for analyses were taken after 14, 28, 165 and 450 days of incubation. The results of the experiment showed that the activity of soil enzymes depended on the content of bioavailable heavy metals; the total concentration of trace elements and H+ were less important. However, considerable differences were found in enzyme activity between naturally and artificially contaminated soils. This indicates that results obtained from other research conducted on freshly contaminated soils cannot be easily transferred to field conditions. The analysed enzymes responded differently to the concentration of bioavailable forms of heavy metals. Alkaline phosphatase was the least tolerant to bioavailable forms of heavy metals, unlike urease, which was the most tolerant soil enzyme. A similar pattern of sensitivity toward trace elements, which could be ordered as Zn > Cd > Cu > Pb, was noticed for dehydrogenases, acid and alkaline phosphatases. Urease was found to be more tolerant to Zn.
6

Impact of afforestation on the limitation of the spread of the pollutions in ground water and in soils

72%
Szajdak L., Zyczynska-Baloniak I., Jaskolska R.
Polish Journal of Environmental Studies
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2003
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tom 12
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nr 4
The investigations were carried out from 1997 to 2001. It was shown the function of the leafy shelter-belt as biogeochemical barrier of total length 114 m by changes of different forms of nitrogen in soil (total, nitrate, ammonium and organic) and in the ground water under shelterbelt and also activity of urease in soil. This shelterbelt is located on two kinds of soil. It was found the impact of the edge of the shelterbelt on the changes of different forms of nitrogen in soil and in ground water and also activity of urease in soils. It was observed that the significant impact on the decrease of nitrogen in ground water and in soils exerts the distance from the edge of shelterbelt. The highest decrease of analyzed compounds was observed in the first sector of shelterbelt (16.5 m). Additionally the effect of eluted cations Ca+2 and Mg+2 on the compensation of pH value of the ground water was also observed.
7
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Transformation of nitrogen compounds in the muckous soils of a forest island

72%
Meysner T., Maryganova V., Szajdak L.
Acta Agrophysica
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2006
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tom 07
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nr 2[133]
8

Production of urease from Helicobacter pylori in transgenic tobacco plants

72%
Brodzik R., Koprowski H., Yusibov V., Sirko A.
Cellular and Molecular Biology Letters
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2000
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tom 05
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nr 3
H. pylori ureA and ureB genes encoding both subunits of urease were expressed transgenically in a low-alkaloid line of tobacco (LA Burley 21). Analysis of transgene expression at both the mRNA and protein levels revealed a significant increase (up to 8-fold) in ammonia concentration correlated with an amount of UreB protein detected in the leaves, and an increase (up to 2-fold) in urease activity in transformants as compared to control plants.
9

Evaluation of the effect of carbamylphosphate synthetase and urease activities in selected strains of wine yeast on the production of ethyl carbamate

72%
Balcerek M., Szopa J. S.
Polish Journal of Food and Nutrition Sciences
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2006
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tom 15/56
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nr 4
The study was aimed at evaluating the enzymatic capacity of selected strains of wine yeast S. cerevisiae for the production of carbamylphosphate synthetase (EC 6.3.4.16) and urease (EC 3.5.1.5) as well as their effect on the production of ethyl carbamate in plum mashes. The experimental material were strains of wine yeast: Syrena, Tokay, Burgund, Bordeaux, Steinberg, originating from the Pure Cultures Collection of the Institute of Fermentation Technology and Microbiology, Technical University of Łódź, and Saccharomyces bayanus yeast by Prochimica Varese SRL company (Italy). Distillery fruit mashes were prepared from plums var. Węgierka łowicka. Under conditions of alcoholic fermentation, the highest activities of NH4+-dependent carbamylphosphate synthetase (45.43 x 10-3 U/mg protein) and urease (0.57 U/mg protein) were observed for the strain Steinberg. Irrespective of the activity (3.2–92.95 U/mg protein) of carbamylphosphate synthetase in the yeast strains examined, the concentration of ethyl carbamate in after-fermentation liquids was at a similar level (<0.01 mg/L). Under conditions of a limited access of oxygen, the maximum activity of urease in S. bayanus yeasts (1.66 U/mg protein), was observed at the stage of preliminary fermentation (yeasts in the stationary phase of growth). Culture media of the Steinberg strain were found to demonstrate a relatively high degree of urea reduction under anaerobic conditions – 19% and a trace concentration of urethane (<0.01 mg/L). A low urolytic activity (0.192 U/mg protein) of yeasts of the Tokay strain was reflected in a relatively high concentration of urethane (0.210 mg/L of 40% spirit) in plum spirit obtained with their participation. Fermentation of plum mash with S. bayanus yeast applied at a dose of 0.5 g d.m./kg, resulted in a decrease in the concentration of ethyl carbamate by 44% (0.07 mg/L of 40% spirit), as compared to the dose of 0.1-0.3 g d.m./kg.
10

Reaction of woods in changes of nitrogen in two kinds of soil

72%
Szajdak L., Matuszewska T.
Polish Journal of Soil Science
|
2000
|
tom 33
|
nr 1
11

Urease activity in soil contaminated with polycyclic aromatic hydrocarbons

58%
Lipinska A., Kucharski J., Wyszkowska J.
Polish Journal of Environmental Studies
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2013
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tom 22
|
nr 5
Urease activity was determined in soil contaminated with four polycyclic aromatic hydrocarbons (PAHs): naphthalene, phenanthrene, anthracene, and pyrene in the amount of 0, 1,000, 2,000, and 4,000 mg·kg⁻¹ DM soil. Organic materials – cellulose, sucrose, and compost – were applied to the samples in the amount of 0 and 9 g·kg⁻¹ DM soil. The experiment was carried out in a laboratory, and soil samples consisted of loamy sand. Soil resistance (RS) and soil resilience (RL) were determined. Soil contamination with PAHs had an adverse effect on urease activity, and naphthalene had the most inhibitory impact on the studied enzyme. Urease activity was significantly determined by the dose of PAH, soil incubation time, and the type of organic material. Soil resistance to PAHs decreased with an increase in contamination levels. The addition of sucrose, cellulose, and compost increased soil's resistance to the toxic effects of naphthalene and phenanthrene. Soil resilience values indicate that polycyclic aromatic hydrocarbons cause long-term impairment of urease activity.
12
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Aktywnosc ureazy w wybranych glebach Polski

58%
Stepniewska Z., Samborska A.
Acta Agrophysica
|
1999
|
tom 22
219-228
Celem badań było określenie aktywności ureazy na wybranych glebach Polski: bielicowych i brunatnych wytworzonych z piasków i glin, lessów, czarnych ziem i mad rzecznych. Badaniom poddano próbki z poziomu 0-10 cm, które pobrano z Banku Gleb Instytutu Agrofizyki PAN. Aktywność ureazy zawierała się w przedziale 0,3256 - 1,7896 pM N-NH4 kg-lh-1. Najniższą aktywność ureazową zanotowano w glebach bielicowych i wynosiła ona 0,33 pM N-NH4 kg-lh-1. W glebach brunatnych wytworzonych z piasków i lessów aktywność ureazy wahała się w granicach 0,55 - 1,00 pM N-NH4 kg-lh-1. Najwyższą aktywność stwierdzono w glebach: czarnych ziemiach, madach rzecznych, glebach murszowych i murszowatych 1,43 - 1,79 pM N-NH4 kg-lh-1. W oparciu o analizę statystyczną otrzymanych wyników można stwierdzić, że aktywność ureazowa pozostaje w ścisłym związku z zawartością materii organicznej.
13

Eco-chemical forest soil indices from a forest fire

58%
Bielinska E. J., Mocek-Plociniak A., Kaczmarek Z.
Polish Journal of Environmental Studies
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2008
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tom 17
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nr 5
665-671
Our paper presents results of investigations aimed at determining correlations between the content of polycyclic aromatic hydrocarbons (PAHs) and the enzymatic activity of a forest soil on an extensive area of forest damaged by a large fire 12 years ago. The investigations comprised experimental plots in the cultivations of Scots pine (Pinus sylvestris L.) and grey alder (Alnus incana L.) MOENCH on three sample surfaces on which different methods of soil preparation were applied. The statistical analysis of the obtained results clearly showed the inhibiting influence of the PAH content on the activity of dehydrogenases, acid phosphatase, alkaline phosphatase and protease, which indicated that the examined soils were loaded with PAHs to such a degree that it was dangerous to living organisms. A highly significant positive correlation was found between urease activity and PAH content.
14
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Wpływ zalesienia gleb porolnych sosną zwyczajną (Pinus sylvestris L.) na ich aktywność enzymatyczną

58%
Acta Agrophysica
|
2017
|
tom 24
|
nr 3
Celem badań było określenie wpływu zalesienia gleb lekkich porolnych sosną na aktywność enzymatyczną gleby. Badania przeprowadzono na terenie Wysoczyzny Lubartowskiej (SE Polska). Wyznaczono dziesięć par stanowisk gleb zalesionych (5 z drzewostanami 14-17-letnimi oraz 5 z drzewostanami 32-36-letnimi) i sąsiadujących z nimi pól uprawnych, a także pięć stanowisk lasów naturalnych z drzewostanami ok. 130-150-letnimi. Próbki gleby pobierano z poziomu próchnicznego A i wzbogacenia Bv, z całej ich miąższości, przy czym z poziomu A gleb zalesionych z trzech kolejnych warstw: 0-5 (AI), 5-10 (AII) i 10-20 cm (AIII). Oznaczono aktywność dehydrogenaz, fosfataz, ureazy oraz proteazy. Stwierdzono, że drzewostany sosnowe po trzydziestu kilku latach wzrostu wywołały zmniejszenie aktywności ureazy i fosfataz oraz zwiększenie aktywności dehydrogenaz. W glebach pod drzewostanami ponad trzydziestoletnimi aktywność ureazy wykazała poziom bardziej zbliżony dla gleb naturalnych borów świeżych niż gleb uprawnych, a aktywność dehydrogenaz odwrotnie – bardziej podobny do gleb uprawnych niż leśnych. W przypadku fosfataz i proteazy nie stwierdzono wyraźnej prawidłowości. Wyniki wskazują, że aktywność enzymatyczna gleby może być przydatnym wskaźnikiem do oceny zmiany właściwości gleb porolnych po ich zalesieniu.
15

Microbial activity in soil inoculated with different mutants of Pseudomonas fluorescens

58%
Kozdroj J.
Acta Microbiologica Polonica
|
1997
|
tom 46
|
nr 1
16
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Wplyw temperatury na parametry kinetyczne Michaelisa-Mentena ureazy glebowej

51%
Samborska A., Stepniewska Z.
Acta Agrophysica
|
2000
|
tom 38
165-174
Celem badań było zbadanie wpływu różnego zakresu temperatur na parametry kinetyczne Michaelisa-Mentena ureazy glebowej. Badaniom poddano próby zawierające czysty enzym (E), glebę nie nawadnianą ściekami wzbogacona enzymem (E + G) i glebę wielokrotnie nawadniana ściekami (G). Aktywność ureazową przy różnych stężeniach mocznika 0,01-3% i w różnych temperaturach: 0, 20, 37, 60°C oznaczano metodą Bonmanti i współ [I], Stałą Michaelisa (Km) i szybkość maksymalną (Vmax) wyznaczono metodą Liweavera-Burka. Aktywność ureazowa (AU) najniższa była w temperaturze 0°C, i wynosiła: 0,02 (µN-NH4 kg-1 h-1 w próbie z enzymem, 0,013 µN-NH4 kg-1 h-1 w kombinacji enzym + gleba, 0,05 (µN-NH4 kg -1h-1 w glebie irygowanej ściekami. Wraz ze wzrostem temperatury obserwowano wzrost aktywności enzymu. W temperaturze 20°C AU przedstawiała się następująco dla: E = 0,10 µN-NH4 kg-1 h-1 E + G = 0,08µN-NH4 kg-1 h -1G = 0,03 µN-NH4 kg-1 h-l. Najwyższe wartości aktywności ureazowej zanotowano w temperaturze 37°C : 0,35 µN-NH4, kg-1 h-1 dla próby zawierającej preparat handlowy, 0,16 µN-NH4 kg-1 h-l w kombinacji gleba wzbogacona enzymem, 0,125 µN-NH4 kg-1 h-1 dla gleby irygowanej ściekami miejskimi Wzrost temperatury do 60°C powodował spadek aktywności enzymatycznej. W zakresie temperatur 0-37°C zanotowano spadek wartości stałej Michaelisa i wzrost szybkości maksymalnej zachodzącej reakcji we wszystkich analizowanych wariantach, natomiast w 60°C twierdzono wzrost Km i spadek wartości Vmax. W oparciu o analizę otrzymanych wyników można stwierdzić że ureaza wykazuje największe powinowactwo względem substratu w temperaturze 37°C, natomiast wzrost temperatury jak również jej spadek zmniejsza dostępność mocznika dla enzymu.
17
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Przemiany substancji organicznej azotowej w zasiarczonej glebie plowej wzbogaconej gnojowica

51%
Jezierska-Tys S.
Acta Agrophysica
|
2000
|
tom 38
105-115
Celem przeprowadzonych badań w doświadczeniu modelowym na glebie płowej wytworzonej z piasku gliniastego mocnego było poznanie wpływu dawki 500 kg S ha-1 r-1 na aktywność proteolityczną, urolityczną, nasilenie amonifikacji i nitryfikacji. Przed wprowadzeniem dawki kwaśnego opadu glebę wzbogacono gnojowicą (60 m3 ha-1 r-1). Przeprowadzone badania wykazały, że najwyższą aktywnością proteolityczną charakteryzowała się gleba wzbogacona gnojowicą z równoczesnym zasiarczeniem. Zasiarczenie gleby oraz wzbogacenie gnojowicą również wpływało stymulująco na aktywność proteolityczną. Na aktywność ureazową gleby największy istotny wpływ miała gnojowica oraz, gnojowica z równoczesnym zasiarczeniem. Na nasilenie procesu amonifikacji hamujący wpływ miało zastosowane zasiarczenie i gnojowica. Natomiast na proces nitryfikacji istotnie stymulujące wpływały zarówno nawożenie w postaci gnojowicy jak i zastosowana dawka kwaśnego opadu.
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