title: Isoflavone aglycones production from isoflavone glycosides by display of beta-glucosidase from Aspergillus oryzae on yeast cell surface.
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.
authors.affiliation: Research Institute, Gekkeikan Sake Co Ltd, Kyoto, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kaya
authors.forename: Junji
authors.initials: J
authors.lastname: Ito
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kotaka
authors.forename: Kengo
authors.initials: K
authors.lastname: Matsumura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Bando
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sahara
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.forename: Seiji
authors.initials: S
authors.lastname: Shibasaki
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
authors.forename: Yoji
authors.initials: Y
authors.lastname: Hata
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology*; D044602:Cellulases / Q000378:metabolism*; D003001:Cloning, Molecular; D005822:Genetic Vectors; D005947:Glucose / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism*; D006868:Hydrolysis; D007529:Isoflavones / Q000096:biosynthesis* / Q000302:isolation & purification; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013379:Substrate Specificity; D014170:Transformation, Genetic
chemical_list: D006027:Glycosides; D007529:Isoflavones; D011993:Recombinant Fusion Proteins; D044602:Cellulases; D005947:Glucose