Open Accessβ-Glucosidase and β-Galactosidase-Mediated Transglycosylation of Steviol Glycosides Utilizing Industrial Byproducts
Author(s) -
Anastasia Zerva,
Koar Chorozian,
Anastasia S. Kritikou,
Nikolaos S. Thomaidis,
Evangelos Topakas
Publication year - 2021
Publication title -
frontiers in bioengineering and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.081
H-Index - 44
ISSN - 2296-4185
DOI - 10.3389/fbioe.2021.685099
Subject(s) - stevioside , steviol , rebaudioside a , stevia rebaudiana , glycoside , chemistry , stevia , aftertaste , bioconversion , food science , taste , biochemistry , organic chemistry , medicine , alternative medicine , pathology , fermentation
Stevia rebaudiana Bertoni is a plant cultivated worldwide due to its use as a sweetener. The sweet taste of stevia is attributed to its numerous steviol glycosides, however, their use is still limited, due to their bitter aftertaste. The transglycosylation of steviol glycosides, aiming at the improvement of their taste, has been reported for many enzymes, however, glycosyl hydrolases are not extensively studied in this respect. In the present study, a β-glucosidase, Mt Bgl3a, and a β-galactosidase, Tt bGal1, have been applied in the transglycosylation of two steviol glycosides, stevioside and rebaudioside A. The maximum conversion yields were 34.6 and 33.1% for stevioside, while 25.6 and 37.6% were obtained for rebaudioside A conversion by Mt Bgl3a and Tt bGal1, respectively. Low-cost industrial byproducts were employed as sugar donors, such as cellulose hydrolyzate and acid whey for Tt bGal1- and Mt Bgl3a- mediated bioconversion, respectively. LC-HRMS analysis identified the formation of mono- and di- glycosylated products from stevioside and rebaudioside A. Overall, the results of the present work indicate that both biocatalysts can be exploited for the design of a cost-effective process for the modification of steviol glycosides.