title: Enzymatic transformation of stevioside using a β-galactosidase from Sulfolobus sp.
abstract: Enzymatic hydrolysis and transgalactosylation of stevioside (St) were investigated using a β-galactosidase from Sulfolobus sp. The hydrolysis yielded steviol as the main final product. Under the optimal transgalactosylation conditions, the highest conversion of stevioside was 87.3% with lactose as a donor, several galactosylated products (St-Gals) were obtained. Metal ions such as Na(+), K(2+), Ca(2+), Ba(2+), Mn(2+) and Mg(2+) (2 mM) did not affect the transgalactosylation activity, while Fe(2+), Fe(3+) and Cu(2+) reduced the transgalactosylation activity of β-galactosidase to 64%, 33% and 18%, respectively.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China. ymxia@jiangnan.edu.cn.
authors.forename: Hui-da
authors.initials: HD
authors.lastname: Wan
authors.forename: Yong-mei
authors.initials: YM
authors.lastname: Xia
mesh_terms: D045786:Diterpenes, Kaurane / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D006868:Hydrolysis; D007785:Lactose / Q000737:chemistry; D016944:Sulfolobus / Q000201:enzymology*; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D045786:Diterpenes, Kaurane; D005960:Glucosides; C012043:stevioside; C012042:steviol; D001616:beta-Galactosidase; D007785:Lactose