Abstract

Abstract The Aspergillus oryzae alpha-amylase cDNA has been cloned into a baker's yeast strain and put under the control of the SUC2 or ACT1 promoters. Integrative YIp and episomal YEp plasmids were constructed and transformants were selected because of their ability to express and export alpha-amylase. In all culture media tested (synthetic medium, flour slurry and bread dough), cells carrying the Aspergillus oryzae alpha-amylase gene under the control of the ACT1 promoter in multicopy plasmids (YEpACT-AMY) gave the highest level of the enzyme. Fermented dough prepared with YEpACT-AMY-containing cells gave a bread with a higher loaf volume, a lower density and a softer crumb than those made with cells containing YIpACT-AMY or with control yeast. The use of [YEpACT-AMY] transformants was also effective at retarding bread firming, increasing shelf-life and freshness of bread. These properties do not appear to be correlated with a large increase in the amount of low molecular weight dextrins.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.