Dekkera bruxellensis
| Dekkera bruxellensis | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dekkera bruxellensis colonies in petri dish |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Dekkera bruxellensis | ||||||||||||
| Van der Walt |
Dekkera bruxellensis (often still known under the name Brettanomyces bruxellensis ) belongs to the yeasts (single-celled fungi) from the Saccharomycetes class. Dekkera bruxellensis isnative to the Senne Valley near Brussels in Belgium - hence the name of the yeast. This yeast lives on the skin of fruit.
Morphology and description
Dekkera bruxellensis has a very variable cell shape. On malt extract - agar it forms ovoid, ellipsoidal to cylindrical elongated cells with 2-7 × 3,5,28 microns. The cells are single, in pairs or in short chains or groups. Pseudo hyphae are also often produced. A coherent, flaky and somewhat slimy sediment is formed. There is a light ring and sometimes a membrane. On malt agar with 2% calcium carbonate shows the smeared culture after six weeks of a restricted, dome-shaped growth. The colony is cream to brownish-cream, smooth or wrinkled. Acetic acid is produced under these conditions . Macroscopically visible colonies look whitish and have a dome-shaped aspect depending on their age and size.
During ascospore formation , the yeast cells are converted directly into asci , which contain four ascospores. These are hat-shaped or spherical with a tangential brim. They are released soon after maturity and tend to stick together. Sporulation is usually sparse. No hybrid types could be recovered from heat-treated asci and most of the strains examined are believed to be homothallic .
Occurrence and ecology
Dekkera bruxellensis occurs worldwide. It was found on the surface of grapes .
meaning
Beer production
Dekkera bruxellensis plays with Brettanomyces lambicus a crucial role in the fermentation process particularly Belgian lambic beers, as well as the Berliner Weisse . Here it contributes to the formation of the desired taste. The technical director of the Carlsberg Brewery, Niels Hjelte Claussen, registered the US Patent Application Number: US1904208464A for the production of English beers "Manufacture of English beers and malt liquors" on May 17, 1904, which was granted on February 20, 1906. It describes the isolation of an organism from old beer bottles and suggests the name Brettanomyces, for the British origin "briton" and "myces" for the characterization as yeast.
Winemaking
In wine production, the flavor components that arise from Brettanomyces yeasts are usually undesirable and are then referred to as wine defects (Brett-Fehlton). In addition to hygienic measures for prophylaxis, polyvinylpyrrolidone is used to reduce the error. Blending with faultless wine is also possible. Brettanomyces yeasts are more alcohol-tolerant than S. cerevisiae and therefore multiply even with higher alcohol contents in sparkling wines and sherry .
Others
Also in the production of Kombucha was Dekkera bruxellensis found.
biochemistry
The metabolic products 4-ethylphenol (leathery), 4-ethylguaiacol (reminiscent of cloves) and 4-ethylcatechol (medicinal) determine the taste significantly.
Systematics
Dekkera bruxellensis is known among oenologists and beer brewers especially under the name Brettanomyces bruxellensis or Brett for short, but it is only the secondary crop form of Dekkera bruxellensis . Hence the name is synonymous . The yeast was made in 1921 by Kuff. and Van Laer under the name Brettanomyces bruxellensis . In 1964 van der Walt separated Dekkera bruxellensis and Dekkera intermedia . Smith then recognized the conspecificity of these and Brettanomyces intermedius in 1990 and also recognized that Dekkera bruxellensis is the major fruit form and Brettanomyces bruxellensis is the minor fruit form.
See also
Individual evidence
- ↑ a b c d e f g h M.Th. Smith: Chapter 25.2: Dekkera bruxellensis van der Walt (1964), in: Cletus Kurtzman, JW Fell, Teun Boekhout (eds.): " The Yeasts A Taxonomic Study, Volume 1 "; Elsevier, BV 2010: p. 375 ff .; ISBN 978-0-444-52149-1 . On-line
- ↑ Pure Culture Fermentation Characteristics of Brettanomyces Yeast Species and Their Use in the Brewing Industry, Chad Yakobson, 2010
- ↑ Brettanomyces bruxellensis occurrence, growth, and effect on wine flavor, Torey Arvik, Thomas Henick-Kling, Practical Winery, 2002
- ↑ a b Nobuyuki Hayashi, Ritsuko Arai, Setsuzo Tada, Hiroshi Taguchi, Yutaka Ogawa: Detection and identification of Brettanomyces / Dekkera sp. yeasts with a loop-mediated isothermal amplification method . In: Food Microbiology . tape 24 , no. 7–8 , 2007, pp. 778–785 , doi : 10.1016 / j.fm.2007.01.007 ( online ).
- ↑ a b Helmut Hans Dittrich: Microbiology of Wine . 1st edition. Eugen Ulmer, Stuttgart 1977, ISBN 3-8001-5807-8 , pp. 223 .
- ↑ United States Patent Office Application Number: US1904208464A
- ↑ The discovery of a third ethylphenol as a contributor to the Brettanomyces miscarriage, Frank Hesford, Katharina Schneider, Swiss magazine for fruit and viticulture, 13/04
- ↑ H. Stender, C. Kurtzman, JJ Hyldig-Nielsen, D. Sørensen, A. Broomer, K. Oliveira, H. Perry-O'Keefe, A. Sage, B. Young, and J. Coull: Identification of Brettanomyces ( Dekkera bruxellensis ) from wine by fluorescence in situ hybridization using peptide nucleic acid probes . In: Appl. Environ. Microbiol . tape 67 , 2001, p. 938-941 , doi : 10.1128 / AEM.67.2.938-941.2001 ( online ).
