Novel Saccharomyces cerevisiae variants slow down the accumulation of staling aldehydes and improve beer shelf-life.

Beer quality generally diminishes over time as staling compounds accumulate through various oxidation reactions. Here, we show that refermentation, a traditional practice where Saccharomyces cerevisiae cells are added to beer prior to bottling, diminishes the accumulation of staling aldehydes. However, commonly used beer yeasts only show a limited lifespan in beer.

Old yeasts, young beer-The industrial relevance of yeast chronological life span.

Much like other living organisms, yeast cells have a limited life span, in terms of both the maximal length of time a cell can stay alive (chronological life span) and the maximal number of cell divisions it can undergo (replicative life span). Over the past years, intensive research revealed that the life span of yeast depends on both the genetic background of the cells and environmental factors. Specifically, the presence of stress factors, reactive oxygen species, and the availability of nutrients profoundly impact life span, and signaling cascades involved in the response to these factors, including the target of rapamycin (TOR) and cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathways, play a central role.

Interspecific hybridization facilitates niche adaptation in beer yeast.

Hybridization between species often leads to non-viable or infertile offspring, yet examples of evolutionarily successful interspecific hybrids have been reported in all kingdoms of life. However, many questions on the ecological circumstances and evolutionary aftermath of interspecific hybridization remain unanswered. In this study, we sequenced and phenotyped a large set of interspecific yeast hybrids isolated from brewing environments to uncover the influence of interspecific hybridization in yeast adaptation and domestication.