13,683
edits
Changes
no edit summary
''Brettanomyces'' has been identified on the skins of fruit <ref name="Schifferdecker"></ref>, as well as vectors (insects) <ref name="Steensels">[http://www.sciencedirect.com/science/article/pii/S0168160515001865 Brettanomyces yeasts — From spoilage organisms to valuable contributors to industrial fermentations. Jan Steensels, Luk Daenen, Philippe Malcorps, Guy Derdelinckx, Hubert Verachtert, Kevin J. Verstrepen. International Journal of Food Microbiology Volume 206, 3 August 2015, Pages 24–38.]</ref>. ''Brettanomyces'' is not considered to be airborne, however studies have found a very small amount of cells in the air at wineries where wine with ''Brettanomyces'' in it was being handled (most of the yeasts found in the air were ''Aureobasidium'' and ''Cryptococcus'', which aren't considered spoilage organisms in beer and wine). These set of studies also determined that very specific methodology was needed in order capture Brett from the air, and indicated that the yeast was "stressed". <ref>[http://www.sciencedirect.com/science/article/pii/S0956713513002284 Screening of yeast mycoflora in winery air samples and their risk of wine contamination. E. Ocón, P. Garijo, S. Sanz, C. Olarte, R. López, P. Santamaría, A.R. Gutiérrez. Food Control Volume 34, Issue 2, December 2013, Pages 261–267.]</ref>. While it is possible for ''Brettanomyces'' to be briefly carried by gusts of air, it only happens in the vicinity where the ''Brettanomyces'' beer or wine is being bottled (more so) or is actively fermenting (less so). Good cleaning and sanitation, and cold temperatures should be employed to keep ''Brettanomyces'' from infecting other equipment, and flying insects are a more likely cause for cross contamination of ''Brettanomyces''.
It is common in scientific literature to see the names ''Dekkera'' and ''Brettanomyces'' used as the genus name, with ''Dekkera'' being the [https://en.wikipedia.org/wiki/Teleomorph,_anamorph_and_holomorph teleomorph] version and ''Brettanomyces'' being the [https://en.wikipedia.org/wiki/Teleomorph,_anamorph_and_holomorph anamorph]. There are five species within the genus of Brettanomyces: ''B. anomola'', ''B. bruxellensis'', ''B. custersianus'', ''B. nanus'', and ''B. naardenensis''. Of these five species, only ''B. anomola'' and ''B. bruxellensis'' have been identified to have a teleomorph version. In their teleomorph version they are referred to as ''Dekkera anomola'' and ''Dekkera bruxellensis'' <ref name="Schifferdecker"></ref>. All of the other names such as the ones often used by yeast labs are derived by old nomenclature that is no longer used([http://www.sciencedirect.com/science/article/pii/S0168160515001865#t0005 click here] for a table that lists old and new taxonomical nomenclature). The addition of small amounts of O2 stimulates glucose fermentation, as well as H+ acceptors such as acetaldehyde, acetone, pyruvic acid and other carbonyl compounds <ref name="yakobson_introduction">[http://www.brettanomycesproject.com/dissertation/introduction/ Yakobson, Chad. The Brettanomyces Project. Introduction. Retrieved 8/11/2015.]</ref>.
Unlike most genres of yeast, ''Brettanomyces'' has the characteristics of being very tolerant to high amounts of alcohol, a pH as low as 2 <ref>[http://www.winesandvines.com/template.cfm?section=news&content=141954 Wines and Vines. New Research on Role of Yeast in Winemaking; report on a presentation by David Mills and Lucy Joseph from UC Davis. 11/14/2014. Retrieved 08/16/2015.]</ref>, and low nitrogen sources <ref name="Schifferdecker"></ref>. Perhaps the most differentiating characteristic of ''Brettanomyces'' is its preference to ferment glucose in the presence of oxygen, which is the opposite preference in [[Saccharomyces]]. This was initially dubbed the "negative Pasteur effect" by Custers, and later the "Custers effect" <ref name="yakobson_introduction"></ref>.