Metabolic energy variation of yeast affects its antioxidant properties in beer brewing

Oxidation destroys the flavor and freshness of the beer, and yeast with improved antioxidant activity would benefit the flavor stability of the beer. The aim of this work was to study the antioxidant networks of lager yeast for brewing industry. Through transcriptome and metabolome analysis, we were able to map changes in anti-oxidant pathways and transcription of genes in lager yeast. Results suggested that metabolic energy variation in yeast might be the main reason for the improved anti-oxidant capacity. Lower metabolic rate kept the yeast at relatively lower respiratory status at the end of fermentation, thereby prolonging the lifespan and potentially supporting its usage in serial fermentations. Up-regulation of mannose synthesis and hexose transport strengthened the cell structure, which may have contributed to the anti-oxidant capacity of yeast. A deeper understanding of the globally regulation pattern of anti-oxidation in lager yeast is expected to support the design of strain development strategies for improved anti-oxidant capacity of yeast for fermentation industry.