Construction of Self-cloning Industrial Brewing Yeast with High-glutathione Production and Low-ADH II Enzyme Activity

Abstract:

Self-cloning strains of industrial brewing yeast were constructed by integrating Saccharomyces cerevisiae genes, γ-glutamylcysteine synthetase gene (GSH1) and copper resistant gene (CUP1) into the locus of alcohol dehydrogenase II (ADH II) gene (ADH2). The self-cloning strains were selected for their resistance to CuSO4 and identified by PCR amplification. The results of ADH II and glutathione (GSH) assay from fermentation with the self-cloning strains in 500ml conical flask showed that ADH II activity decreased to 65% and GSH content was 1.3 fold compared with that of host yeasts. The self-cloning strains do not contain any heterologous DNA; they may be more acceptable to the public.