The effects of carbendazim on metabolic pathways of Saccharomyces cerevisiae Saflager S-189 and beer characteristics

Carbendazim (CBZ) is a broad-spectrum fungicide commonly used in agriculture, but its residue can contaminate beer ingredients, potentially affecting Saccharomyces cerevisiae and beer quality. In this work, the effect of CBZ on Saccharomyces cerevisiae Saflager S-189 (S-189) and beer quality was investigated. The results demonstrated that S-189 was inhibited at concentrations equal to or exceeding 150 μg/kg of CBZ, reducing its growth rate, cell number, viability, and damaging cell structure. The CBZ disrupted multiple metabolic pathways in S-189, including amino acid biosynthesis, tRNA biosynthesis, and ABC transporters, and negatively affected energy metabolism, antioxidant activity, nutrient transport, and fermentation performance. Compared with the control group, the fermentation degree, alcohol content, and total acidity of beer fermented with 300 μg/kg CBZ-contaminated wort decreased, while the true concentration, pH, turbidity, and alcohol-ester ratio increased. Furthermore, CBZ changed the content of key flavor substances in beer, which affected the flavor quality of beer.