Constructing an amylolytic brewing yeast Saccharomyces pastorianus suitable for accelerated brewing.
An amylolytic brewing yeast Saccharomyces pastorianus, free of vector sequences and drug-resistance genes, was constructed by disrupting the alpha-acetolactate synthase gene and introducing the alpha-amylase gene as a selective marker. The resulting recombinant strain was able to utilize starch as the sole carbon source and its alpha-acetolactate synthase activity was lowered by 30%. Fermentation tests confirmed that the diacetyl concentration and the residual oligosaccharide were reduced by 70% and 25%, respectively, in fermented wort by the recombinant strain, while the brewing performance of the recombinant strain was retained.
Liu
Zengran
Z
Bioscience and Bioengineering College, Hebei Economics and Business University, 47 Xuefu Road, Shijiazhuang 050061, PR China.
Zhang
Guangyi
G
Liu
Shigui
S