A comparative study of the performance of solid supported and soluble urease for the enzymatic hydrolysis of urea

2007 ◽  
Vol 55 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Günay Demirel ◽  
GÜNeri Akovali ◽  
Abdurrahman Tanyolac ◽  
Nesrin Hasirci
Keyword(s):  
Enzymatic Hydrolysis ◽  
Comparative Study ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

Comparative study of enzymatic hydrolysis of α/β- and γ-gliadins

Nahrung/Food ◽  
1997 ◽  
Vol 41 (4) ◽  
pp. 201-207 ◽  
Author(s):  
C. Legay ◽  
Y. Popineau ◽  
S. Bérot ◽  
J. Guéguen
Keyword(s):  
Enzymatic Hydrolysis ◽  
Comparative Study ◽  
Hydrolysis Of

Comparative study on different pretreatment on enzymatic hydrolysis of corncob residues

2020 ◽  
Vol 295 ◽  
pp. 122244 ◽  
Author(s):  
Wei Liu ◽  
Ruijie Wu ◽  
Bing Wang ◽  
Yingying Hu ◽  
Qingxi Hou ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Comparative Study ◽  
Hydrolysis Of

A comparative study on enzymatic hydrolysis of kenaf from two different harvest time-points, with- and without pretreatment

2015 ◽  
Vol 76 ◽  
pp. 237-243 ◽  
Author(s):  
Seung Gon Wi ◽  
Su-Bae Kim ◽  
Dae-Seok Lee ◽  
Ho Myeong Kim ◽  
Hyeun-Jong Bae
Keyword(s):  
Enzymatic Hydrolysis ◽  
Comparative Study ◽  
Harvest Time ◽  
Time Points ◽  
Hydrolysis Of

Monolithic gelation of chitosan solutions via enzymatic hydrolysis of urea

2006 ◽  
Vol 64 (3) ◽  
pp. 419-424 ◽  
Author(s):  
A. Chenite ◽  
S. Gori ◽  
M. Shive ◽  
E. Desrosiers ◽  
M.D. Buschmann
Keyword(s):  
Enzymatic Hydrolysis ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

scholarly journals A Study on the Hydrolysis of Urea Contained in Wastewater and Continuous Recovery of Ammonia by an Enzymatic Membrane Reactor

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1703
Author(s):  
Mukhtar Nuhu Yahya ◽  
Hüseyin Gökçekuş ◽  
Derin Orhon ◽  
Bülent Keskinler ◽  
Ahmet Karagunduz ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Enzymatic Hydrolysis ◽  
Membrane Reactor ◽  
Ammonium Nitrogen ◽  
Feed Concentration ◽  
Filtration Membrane ◽  
Urease Enzyme ◽  
Ultra Filtration ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

1. Background: Urea is the main product of the nitrogenous breakdown of protein metabolism in mammals. In this study, process intensification for enzymatic hydrolysis of urea by urease enzyme (jack bean urease) was examined in a membrane reactor. 2. Methods: Batch and continuous enzymatic hydrolysis reactions were performed at different substrate concentrations to determine the digestibility and affinity of the substrate with that of the enzyme. The hydrolysate samples were obtained by an optimized continuous enzyme membrane reactor (EMR) coupled with an ultra-filtration membrane (250 kDa). Feed concentration varied from 100 to 500 mg/L. Laboratory experiments were conducted at room temperature (20 ± 1 °C), with a flow rate of 20 mL/min, urease concentration of 0.067 g/L, ionic strength (I = 0, 0.01, 0.05), and ammonium nitrogen addition of (0, 100 mg/L, 200 mg/L, 500 mg/L). Moreover, the effect of ionic strength, ammonium nitrogen concentration, feed concentration, and enzyme concentration on urea hydrolysis was examined. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX) analysis were used to identify the physicochemical properties as well as the elemental composition of the Ultra-Filtration membrane used in this study. 3. Results: The study revealed that higher ionic strength and higher concentrations of NH4SO2 and ammonium nitrogen (NH3-N) inhibithydrolysis of urea by reducing the urease enzyme activity in the system over time. 4. Conclusions: Herein, a sustainable alternative for the conversion of urea to ammonia by utilizing urease in an EMR was demonstrated.

Jack bean urease (EC 3.5.1.5). V. On the mechanism of action of urease on urea, formamide, acetamide, N-methylurea, and related compounds

1980 ◽  
Vol 58 (12) ◽  
pp. 1335-1344 ◽  
Author(s):  
Nicholas E. Dixon ◽  
Peter W. Riddles ◽  
Carlo Gazzola ◽  
Robert L. Blakeley ◽  
Burt Zerner
Keyword(s):  
Enzymatic Hydrolysis ◽  
Mechanism Of Action ◽  
Active Site ◽  
Ph Dependence ◽  
Jack Bean Urease ◽  
Nickel Ion ◽  
Jack Bean ◽  
First Time ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

Acetamide and N-methylurea have been shown for the first time to be substrates for jack bean urease. In the enzymatic hydrolysis of urea, formamide, acetamide, and N-methylurea at pH 7.0 and 38 °C, kcat has the values 5870, 85, 0.55, and 0.075 s−1, respectively. The urease-catalyzed hydrolysis of all these substrates involves the active-site nickel ion(s). Enzymatic hydrolysis of the following compounds could not be detected: phenyl formate, p-nitroformanilide, trifluoroacetamide, p-nitrophenyl carbamate, thiourea, and O-methylisouronium ion. In the enzymatic hydrolysis of urea, the pH dependence of kcat between pH 3.4 and 7.8 indicates that at least two prototropic forms are active. Enzymatic hydrolysis of urea in the presence of methanol gave no detectable methyl carbamate. A mechanism of action for urease is proposed which involves initially an O-bonded complex between urea and an active-site Ni2+ ion and subsequently an O-bonded carbamato–enzyme intermediate.

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