Urease testing and yeast taxonomy

Booth, J. Leland; Vishniac, Helen S.

doi:10.1139/m87-069

Cited by 33 publications

(12 citation statements)

References 35 publications

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“…Hydrolysis of urea is a characteristic of a few ascogenous yeasts, such as Schizosaccharomyces pombe, Y. lipolytica and Lipomyces spp. [20]. Only the R. mucilaginosa and Y. lipolytica isolates possessed a signi¢cant ability to hydrolyse pork fat in vitro.…”

Section: Yeasts Isolated During the Ripening Processesmentioning

confidence: 96%

A survey of yeasts in traditional sausages of southern Italy

Gardini

Suzzi

Lombardi³

et al. 2001

FEMS Yeast Research

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The evolution of the yeast population during manufacturing and ripening of 'salsiccia sotto sugna', a typical salami of the Lucania region (southern Italy), was investigated. Four different batches, produced in four farms in Lucania, were studied. Each batch showed a specific yeast population, and the most frequently isolated yeasts belonged to Debaryomyces hansenii and its anamorph Candida famata, and Rhodotorula mucilaginosa. Yarrowia lipolytica was isolated from three sausage batches. The Y. lipolytica isolates were further characterised, in particular for their lipolytic activity on pork fat. Lipolytic activity was maximal at pH 5.5, with oleic and palmitic acids as major free fatty acids produced. The use of randomly amplified polymorphic DNA-polymerase chain reaction allowed the detection of a high genetic heterogeneity among the isolates phenotypically assigned to the species Y. lipolytica.

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Section: Yeasts Isolated During the Ripening Processesmentioning

confidence: 96%

A survey of yeasts in traditional sausages of southern Italy

Gardini

Suzzi

Lombardi³

et al. 2001

FEMS Yeast Research

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“…Urease is common in nature and is produced by a wide range of organisms. Urease has been found in several species of bacteria, fungi, algae, plants, and invertebrates (Bekheet and Syrett 1977;Booth and Vishniac 1987;Cook 1976;Frankenberger and Tabatabai 1982;Hanlon 1975;Sumner 1926). For many organisms, urease plays an important role in nitrogen metabolism or as a defense mechanism.…”

Section: The Enzymatic Degradation Of Urea To Ammonia By Ureasementioning

confidence: 99%

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

Sigurdarson

Svane

Karring

2018

Rev Environ Sci Biotechnol

239

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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“…Yamazaki & Komagata (25) concluded from electrophoretic comparison of 7 enzymes in 108 strains of Rhodotorula and Rhodosporidium that this technique was useful in establishing taxonomic relationships among red yeasts. Urease testing is also of value in yeast taxonomy (26).…”

Section: Enzymesmentioning

confidence: 99%

Chemotaxonomy of yeasts

Olsen

1990

Acta Odontologica Scandinavica

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The present review deals with chemotaxonomic methods for yeasts. DNA base composition, which is expressed as molar percentages of guanine plus cytosine (G + C), is fitted for description of a new species and serves exclusionary functions. G + C content range among species within a genus is often 10% or less. Larger ranges may indicate an amalgam of genera. Typing and mapping of DNA may also be used for taxonomy. Strains showing 65% or greater relatedness after DNA-DNA hybridization may be considered members of the same species. With rRNA-DNA homology assessment, intrageneric relationships established are not usually meaningful, but intergeneric distances can be resolved. rRNA can be used for examining phylogenetic diversity of yeasts and alloenzyme variation to calculate genetic distances among large yeast populations. Furthermore, heterogeneity in coenzyme Q pattern, cytochrome spectra, composition of cell wall glucan, mannan, and chitin, and cellular fatty acids may serve chemotaxonomic purposes.

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Urease testing and yeast taxonomy

Cited by 33 publications

References 35 publications

A survey of yeasts in traditional sausages of southern Italy

A survey of yeasts in traditional sausages of southern Italy

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

Chemotaxonomy of yeasts

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