Isoflavone aglycones production from isoflavone glycosides by display of beta-glucosidase from Aspergillus oryzae on yeast cell surface.
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.
Kaya
Masahiko
M
Research Institute, Gekkeikan Sake Co Ltd, Kyoto, Japan.
Ito
Junji
J
Kotaka
Atsushi
A
Matsumura
Kengo
K
Bando
Hiroki
H
Sahara
Hiroshi
H
Ogino
Chiaki
C
Shibasaki
Seiji
S
Kuroda
Kouichi
K
Ueda
Mitsuyoshi
M
Kondo
Akihiko
A
Hata
Yoji
Y
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
D006027:Glycosides; D007529:Isoflavones; D011993:Recombinant Fusion Proteins; D044602:Cellulases; D005947:Glucose