SoilScience • Volume 175, Number 11, November 2010 Urease is one of the most thoroughly studied soil enzymes because it greatly influences the fate and performance of a widely used fertilizer (urea) (Bremner and Mulvaney, 1978; Ma et al., 1999; Tate, 2002). Urea was reported to be taken up by microorganisms, such as Corynebacterium glutamicum and Paxillus involutus (Jahns and Kaltwasser, 1989; ...

The role in virulence of Actinobacillus pleuropneumoniae urease activity was investigated. A urease-negative mutant was isolated following transposon mutagenesis with a mini-Tn10 derivative. Both the parent strain and the urease-negative mutant exhibited identical LD50 values in a murine infection model. Pig challenge confirmed that the urease-negative mutant was fully virulent, since experimen...

The role of urease in Helicobacter pylori adherence to and internalization by Kato III cells was investigated. Kato III cells were incubated with wild-type strains (N6 or P1), with isogenic mutants lacking urease (N6ureB::TnKm or P1ureA::TnMax5) or producing the inactive apoprotein (N6ureG::TnKm), and with urease-positive clones recovered after complementation of N6ureB::TnKm with ureAB. Bacter...

Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a ur...

The identity of the enzyme urease with the octahedral globulin crystals isolated by the senior author from the jack bean in 1926 (1) has been challenged by Waldschmidt-Leitz and Steigerwaldt (2). These investigators published a paper in which they claimed that crystalline urease is not inactivated at pH 7.0 by incubation with trypsin or papain, while the protein component of the urease undergoe...

Ureaplasmas killed mice within 5 min after intravenous injection. The 50% lethal dose of whole ureaplasmal organisms was 32 micrograms per mouse, a value also found for crystalline jackbean urease. The reaction was specific to urease, since protection was afforded by intraperitoneal injection of 200 micrograms of flurofamide, a potent urease inhibitor. The finding that a similar lethal effect w...

In this study the effects of Fe2O3 and Fe3O4 magnetic nanoparticles and EDTA on urease activity was investigated. The effect of nano-Fe2O3 and nano-Fe3O4 on urease activity were investigated. Urease activity was studies by UV-Vis spectrophotometry at 40 °C at pH = 7.2 using sodium phosphate as buffer. Measurements were carried out using 0.075 mg/ml of urease and a range of nano-Fe2O3 and nano-F...

Proteus mirabilis, a common agent of nosocomially acquired and catheter-associated urinary tract infection, is the most frequent cause of infection-induced bladder and kidney stones. Urease-catalyzed urea hydrolysis initiates stone formation in urine and can be inhibited by acetohydroxamic acid and other structural analogs of urea. Since P. mirabilis urease is inducible with urea, there has bee...

Globally, urea is the most widely used nitrogen fertilizer and is made accessible to plants via the urease reaction. However, sequence information for the plant enzyme is scarce. A cDNA encoding urease from soybean (Glycine max) has been cloned and sequence information has been obtained for two alleles (11 and 19 kbp, respectively) of the potato (Solanum tuberosum, cv. Desiree) urease gene and ...