Dekkera Brettanomyces

Chatonnet, R, Dubourdieu, D., Boidron, J.N. (1995) The influence of Brettanomyces/Dekkera sp. yeasts and lactic acid bacteria on the ethylphenol content of red wines. Am. J. Enol. Vitic., 46, 463-468. 

Wineries commonly reuse their barrels. The useful lifetime of a barrel, however, is between five and six years, not just because of the depletion of volatile components that can leach into the wine but also because of the growth of unwanted microorganisms such as Brettanomyces/Dekkera. This yeast can synthesize... 

Malfeito-Eerreira, M. (2005). Avances recientes en el control de Brettanomyces/Dekkera bruxel-lensis en vinos. In Enotour 2005 Agrovin, Zaragoza, Spain, 28-30 June. 

Mitrakul, C. Evaluation of DNA fingerprinting methods for identification of Brettanomyces/Dekkera yeasts from wines, thesis, Cornell University, 1997. 

Ethyl phenols are a result of enzymatic activities linked to the decarboxylation of cinnamic acids and the subsequent reduction in vinyl phenols caused by the Brettanomyces/Dekkera yeast genus (Chatonnet et al., 1992), apart from very small quantities produced in peculiar... 

Mousy taint is a microbiological defect of wine due to Brettanomyces/ Dekkera yeasts, as well as certain lactic acid bacteria, such as Leuconostoc oenos (Oenococcus oeni) and Lactobacillus. Brettanomyces yeasts are frequently found in wooden casks. Mousy taint can occur particularly... 

By isolating acetic bacteria, lactic bacteria and yeasts from red wines with phenol off-odors, it was demonstrated that Brettanomyces/Dekkera yeasts were the only microorganisms capable of producing several milligrams of ethyl-phenols per liter of wine. The species most prevalent in wine is Brettanomyces bruxellensis (Chatonnet et al, 1992b). 

Table 8.8. Impact of free SO2 content when wine is put into the barrel on the development of Brettanomyces/Dekkera sp. and on the formation of ethyl-phenols in red wines (Chatonnet et ah, 1993a)...

Probably the most significant stumbling block in successful routine laboratory identification of Brettanomyces and Dekkera lies in the fundamental requirements of taxonomic guides to demonstrate the presence (or absence) of a sexual phase in the life cycle of the yeast. Dekkera requires a sporulation medium that includes augmentation with several vitamins (see Procedure 3.5.2). Required in microgram and milligram amounts, these nutrients are not easily and routinely supplied in most production-oriented laboratories. Hagan (1979) notes that even under ideal conditions, relatively poor sporulation (<1%) is observed. As a result, suspect isolates are often reported as Brett-like or Brettanomyces/Dekkera. ... 

Chardonnay and Sauvignon Blanc. Schanderl and Draczynski (1952) and, subsequently, Van de Water (1990) report isolation of Brettanomyces/Dekkera from methode champenoise sparkling wine en tirage. Van de Water further notes that both appear to be less sensitive than Saccharomyces to carbon dioxide and concludes that they may become a more widespread problem as California sparkling wine production increases. 

Van der Walt (1970) suggests that in the case of fastidious yeast, such as Brettanomyces/Dekkera, cell suspensions be prepared in stock vitamin solution (see 3.5.2 for preparation). In this case, and in general, it is advisable to prepare a control to detect carryover of nitrogen or carbon from the original culture. The control, here, consists of only basal medium and yeast. 

Where the time frame for results is crucial, such as in samples off the bottling line, all plating techniques suffer from the common problem of significant lag time before plates can be examined. In the case of most yeasts, 72 h of incubation is the norm, but with Brettanomyces/Dekkera and LAB, up to 1 week is required. Thus, techniques such as microscopic examination are continually being evaluated. 

CiANi, M. and L. Ferraro. 1997. Role of oxygen on acetic acid production by Brettanomyces/Dekkera in winemaking./. Sci. Food Agric. 75 489-495. 

Egli, G.M. and T. Henigk-Kling. 2001. Identification of Brettanomyces/Dekkera species based on polymorphism in the rRNA internal transcribed spacer region. Am.J. Enol. Vitic. 52 241—247. 

Silva, P., H. Cardoso, and H. Geros. 2004. Studies on the wine spoilage capacity of Brettanomyces/Dekkera spp. Am.]. Enol. Vitic. 55 65-72. 

---