Urease activity in soils

Lloyd, A. B.; Sheaffe, M. Jane

doi:10.1007/bf00018046

Cited by 166 publications

(55 citation statements)

References 11 publications

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“…One study found that 17-30% of bacteria isolated from six soil samples produced urease (Lloyd and Sheaffe 1973). The isolated ureolytic bacteria included both anaerobes, micro-aerophiles, and aerobes, illustrating the wide range of ureolytic bacteria.…”

Section: Bacterial Ureasementioning

confidence: 99%

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

Sigurdarson

Svane

Karring

2018

Rev Environ Sci Biotechnol

244

129

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Ammonia emissions from the agricultural sector give rise to numerous environmental and societal concerns and represent an economic challenge in crop farming, causing a loss of fertilizer nitrogen. Ammonia emissions from agriculture originate from manure slurry (livestock housing, storage, and fertilization of fields) as well as urea-based mineral fertilizers. Consequently, political attention has been given to ammonia volatilization, and regulations of ammonia emissions have been implemented in several countries. The molecular cause of the emission is the enzyme urease, which catalyzes the hydrolysis of urea to ammonia and carbonic acid. Urease is present in many different organisms, encompassing bacteria, fungi, and plants. In agriculture, microorganisms found in animal fecal matter and soil are responsible for urea hydrolysis. One strategy to reduce ammonia emissions is the application of urease inhibitors as additives to urea-based synthetic fertilizers and manure slurry to block the formation of ammonia. However, treatment of the manure slurry with urease inhibitors is associated with increased livestock production costs and has not yet been commercialized. Thus, development of novel, environmentally friendly and cost-effective technologies for ammonia emission mitigation is important. This mini-review describes the challenges associated with the volatilization of ammonia in agriculture and provides an overview of the molecular processes of urea hydrolysis and ammonia emissions. Different technologies and strategies to reduce ammonia emissions are described with a special focus on the use of urease inhibitors. The mechanisms of action and efficiency of the most important urease inhibitors in relation to agriculture will be briefly discussed.

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Section: Bacterial Ureasementioning

confidence: 99%

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

Sigurdarson

Svane

Karring

2018

Rev Environ Sci Biotechnol

244

129

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“…Two imidazole N atoms are bound to each Ni atom; a carboxylate group and a water molecule fill the remaining coordination site of the metal ion. The ability to hydrolyze urea is found to vary from 17 to 70% for soil bacteria and from 78 to 98% for soil fungi (Lloyd & Sheaffe, 1973;Roberge & Knowles, 1967). Although soil urease is considered to be of microbial origin (Skujins, 1976), there is evidence to suggest that some urease activity may be derived from plants (Frankenberger & Tabatabai, 1982).…”

Section: Wwwintechopencommentioning

confidence: 99%

Emissions of Nitrous Oxide (N2O) and Di-Nitrogen (N2) from the Agricultural Landscapes, Sources, Sinks, and Factors Affecting N2O and N2 Ratios

Zaman¹,

Nguyen²,

Šimek³

et al. 2012

Greenhouse Gases - Emission, Measurement and Management

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“…The most efficient biogeochemical pathway for MICP involves the microbial hydrolysis of urea, which is catalyzed by the microbial enzyme urease (urea amidohydrolase, EC 3.5.1.5) (De Muynck et al, 2010a;Lloyd and Sheaffe 1973). The enzymatic hydrolysis of urea is approximately 10 14 times faster than the spontaneous reaction (Jabri et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

“…The enzymatic hydrolysis of urea is approximately 10 14 times faster than the spontaneous reaction (Jabri et al, 1995). Ureahydrolyzing microorganisms, both eukaryotes and prokaryotes, are ubiquitous in natural soils, and urea hydrolysis is a process common to soils worldwide (Bremner and Mulvaney, 1978;Lloyd and Sheaffe, 1973;Mobley and Hausinger, 1989). Urea is initially hydrolyzed to carbamate and ammonia (Reaction R1; Mobley and Hausinger, 1989).…”

Section: Introductionmentioning

confidence: 99%

Accelerated microbial-induced CaCO<sub>3</sub> precipitation in a defined coculture of ureolytic and non-ureolytic bacteria

Gat

Tsesarsky

Shamir³

et al. 2014

Biogeosciences

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Abstract. Microbial-induced CaCO 3 precipitation (MICP) is an innovative technique that harnesses bacterial activity for the modification of the physical properties of soils. Since stimulation of MICP by urea hydrolysis in natural soils is likely to be affected by interactions between ureolytic and non-ureolytic bacteria, we designed an experiment to examine the interactions between ureolytic and non-ureolytic bacteria and the effect of these interactions on MICP. An artificial groundwater-based rich medium was inoculated with two model species of bacteria, the ureolytic species Sporosarcina pasteurii and the non-ureolytic species Bacillus subtilis. The control treatment was inoculated with a pure culture of S. pasteurii. The following parameters were monitored during the course of the experiment: optical density, pH, the evolution of ammonium, dissolved calcium and dissolved inorganic carbon. The results showed that dissolved calcium was precipitated as CaCO 3 faster in the mixed culture than in the control, despite less favorable chemical conditions in the mixed culture, i.e., lower pH and lower CO 2− 3 concentration. B. subtilis exhibited a considerably higher growth rate than S. pasteurii, resulting in higher density of bacterial cells in the mixed culture. We suggest that the presence of the non-ureolytic bacterial species, B. subtilis, accelerated the MICP process, via the supply of nucleation sites in the form of non-ureolytic bacterial cells.

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Urease activity in soils

Cited by 166 publications

References 11 publications

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

Emissions of Nitrous Oxide (N2O) and Di-Nitrogen (N2) from the Agricultural Landscapes, Sources, Sinks, and Factors Affecting N2O and N2 Ratios

Accelerated microbial-induced CaCO<sub>3</sub> precipitation in a defined coculture of ureolytic and non-ureolytic bacteria

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Urease activity in soils

Cited by 166 publications

References 11 publications

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

The molecular processes of urea hydrolysis in relation to ammonia emissions from agriculture

Emissions of Nitrous Oxide (N2O) and Di-Nitrogen (N2) from the Agricultural Landscapes, Sources, Sinks, and Factors Affecting N2O and N2 Ratios

Accelerated microbial-induced CaCO&lt;sub&gt;3&lt;/sub&gt; precipitation in a defined coculture of ureolytic and non-ureolytic bacteria

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Accelerated microbial-induced CaCO<sub>3</sub> precipitation in a defined coculture of ureolytic and non-ureolytic bacteria