Isoflavone aglycones production from isoflavone glycosides by display of beta-glucosidase from Aspergillus oryzae on yeast cell surface

Appl Microbiol Biotechnol. 2008 May;79(1):51-60. doi: 10.1007/s00253-008-1393-6. Epub 2008 Mar 14.

Abstract

For efficient production of isoflavone aglycones from soybean isoflavones, we isolated three novel types of beta-glucosidase (BGL1, BGL3, and BGL5) from the filamentous fungi Aspergillus oryzae. Three enzymes were independently displayed on the cell surface of a yeast Saccharomyces cerevisiae as a fusion protein with alpha-agglutinin. Three beta-glucosidase-displaying yeast strains hydrolyzed isoflavone glycosides efficiently but exhibited different substrate specificities. Among these beta-glucosidases, BGL1 exhibited the highest activity and also broad substrate specificity to isoflavone glycosides. Although glucose released from isoflavone glycosides are generally known to inhibit beta-glucosidase, the residual ratio of isoflavone glycosides in the reaction mixture with BGL1-displaying yeast strain (Sc-BGL1) reached approximately 6.2%, and the glucose concentration in the reaction mixture was maintained at lower level. This result indicated that Sc-BGL1 assimilated the glucose before they inhibited the hydrolysis reaction, and efficient production of isoflavone aglycones was achieved by engineered yeast cells displaying beta-glucosidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus oryzae / enzymology*
  • Cellulases / metabolism*
  • Cloning, Molecular
  • Genetic Vectors
  • Glucose / metabolism
  • Glycosides / metabolism*
  • Hydrolysis
  • Isoflavones / biosynthesis*
  • Isoflavones / isolation & purification
  • Plasmids
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology
  • Substrate Specificity
  • Transformation, Genetic

Substances

  • Glycosides
  • Isoflavones
  • Recombinant Fusion Proteins
  • Cellulases
  • Glucose