Kvasny Prum. 2011; 57(7-8): 277-284 | DOI: 10.18832/kp2011032

Stress responses in brewing yeast.Peer-reviewed article

Karel SIGLER, Dagmar MATOULKOVÁ

¹ Mikrobiologický ústav, AV ČR, v.v.i., Vídeňská 1083, 142 20 Praha 4

² Výzkumný ústav pivovarský a sladařský, a.s., Lípová 15, 120 44 Praha 2

Even in nature, yeast cells are exposed to a combination of stressful conditions. When used for industrial production, as in brewery, they are subject to additional manmade stresses, and/or the natural environmental stresses are intensified. During the brewing process yeast cells are challenged, e.g., by variations in temperature, oxygen concentration and pH, hypo- and hyperosmotic stress, hydrostatic and chemical stress (ethanol, malt and hop phenolics, malt antimicrobial compounds, adjunct components, CO2 overpressure, etc.), and changing levels of nutrients. Other stresses, include, e.g., acid washing to remove bacteria before repitching, or centrifugation causing hydrodynamic stress. To lower operating costs, reduce processing times and maximize revenue [2] breweries adopt and evolve continuously new systems that potentially amplify and/or extend the existing stresses. Here we tried to summarize briefly the main features of both environmental and brewing stresses, characterize the types of stress responses of yeast cells, and point out the specificities of brewing yeast strains and the conditions of their use for beer production, and the way in which they reflect in the stress responses of brewing yeast.Even in nature, yeast cells are exposed to a combination of stressful conditions. When used for industrial production, as in brewery, they are subject to additional manmade stresses, and/or the natural environmental stresses are intensified. During the brewing process yeast cells are challenged, e.g., by variations in temperature, oxygen concentration and pH, hypo- and hyperosmotic stress, hydrostatic and chemical stress (ethanol, malt and hop phenolics, malt antimicrobial compounds, adjunct components, CO2 overpressure, etc.), and changing levels of nutrients. Other stresses, include, e.g., acid washing to remove bacteria before repitching, or centrifugation causing hydrodynamic stress. To lower operating costs, reduce processing times and maximize revenue [2] breweries adopt and evolve continuously new systems that potentially amplify and/or extend the existing stresses. Here we tried to summarize briefly the main features of both environmental and brewing stresses, characterize the types of stress responses of yeast cells, and point out the specificities of brewing yeast strains and the conditions of their use for beer production, and the way in which they reflect in the stress responses of brewing yeast.

Keywords: yeast, stress, stress responses

Received: May 2, 2011; Accepted: June 1, 2011; Published: July 1, 2011