Abstract
In this work the potential of comparative transcriptomics was explored of Saccharomyces (S.) cerevisiae and S. pastorianus for their discrimination. This way an alternative should be demonstrated to comparative genomics, which can be difficult as a result of their aneuoploid genomes composed of mosaics of the parental genomes. Strains were selected according to their application in beer brewing, i.e. top and bottom fermenting yeasts. Comparative transcriptomics was performed for four strains each of commercially available S. cerevisiae (top fermenting) and Saccharomyces pastorianus (bottom fermenting) brewing yeasts grown at two different temperatures to mid-exponential growth phase. A non-reference based approach was chosen in the form of alignment against a de novo assembled brewery-associated pan transcriptome to exclude bias introduced by manual selection of reference genomes. The result is an analysis workflow for self-contained comparative transcriptomics of Saccharomyces yeasts including, but not limited to, the analysis of core and accessory gene expression, functional analysis and metabolic classification. The functionality of this workflow is demonstrated along the principal differentiation of accessory transcriptomes of S. cerevisiae versus S. pastorianus strains. Hence, this work provides a concept enabling studies under different brewing conditions.
Highlights
IntroductionThe brewing of beer is a chemically complex and lastly highly controlled biotechnological process
Brewing and yeastsThe brewing of beer is a chemically complex and lastly highly controlled biotechnological process
This work was conducted to demonstrate the potential of comparative transcriptomics to delineate brewing yeast types despite their complex chromosomal settings
Summary
The brewing of beer is a chemically complex and lastly highly controlled biotechnological process. According to the German brewers’ association there are more than 40 malt varieties, 250 different hops and over 400 yeast strains to choose from, not to mention the staggering differences in water quality. Most of the beers result from fermentation with a very limited number of yeast strains, e.g. in Germany mostly four strains with one single strain accounting for approximately 65% are used. The unexploited combinations and possibilities to use different yeasts strains for the development of new beers are virtually endless [1]. Saccharomyces brewing yeasts can be categorised into the two species Saccharomyces (S.) cerevisiae and S. pastorianus.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
