Genetic Engineering of Yeast: Construction of Strains That Degrade β-Glucans with the Aid of a Barley Gene¹

1 Paper presented at the 53rd Annual Meeting, Cincinnati, OH, May–June 1987.

Abstract

A cDNA gene encoding the mature form of a barley (1→3, 1→4)-β-glucanase, fused in frame with a DNA fragment coding for an α-amylase signal peptide was inserted in replicating yeast plasmids behind the promoter region of the alcohol dehydrogenase I gene from Saccharomyces cerevisiae. Yeast cells carrying such plasmids synthesize (1→3,1→4)-β-glucanase, and the enzyme is exported to the culture medium. Small-scale fermentation experiments with β-glucanase-producing S. cerevisiae have shown that the amount of β-glucanase released to the culture medium is sufficient to degrade up to 500 mg/L of β-glucan during a seven-day fermentation period at 10° C. The β-glucanase expression unit (promoter, β-glucanase cDNA gene, and terminator) was inserted in an integrating vector to transfer the barley β-glucanase gene into the genome of brewing yeast strains. After transformation of yeast to G418 resistance, β-glucanase activity was detected in the culture medium.

• β-Glucanase
• Barley
• Brewing
• Genetic engineering

View correction statement:

Erratum