
CHARACTERIZATION OF THERMOSTABLE BETA-1,4-GALACTANASE AND ITS APPLICATION IN HYDROLYSIS OF PECTIN FROM SWEET POTATO (Ipomoea batatas (L.) Lam) PEELS
Author(s) -
Noor Faizah Ismail,
Dayang Norulfairuz Abang Zaidel,
Mohd-Noor Mat-Isa
Publication year - 2021
Publication title -
jurnal teknologi/jurnal teknologi
Language(s) - English
Resource type - Journals
eISSN - 2180-3722
pISSN - 0127-9696
DOI - 10.11113/jurnalteknologi.v83.17198
Subject(s) - galactan , pectin , hydrolysis , chemistry , ipomoea , thermophile , galactose , enzyme , biochemistry , polysaccharide , glycoside hydrolase , food science , chromatography , botany , biology
Galactooligosaccharides (GOS) synthesis has received much attention due to its prebiotic function. Beta-1,4-galactanase responsible for the hydrolysis of galactan plays an important role in producing GOS from biodegradation of this pectin component. In this study, beta-1,4-galactanase (BgcGC) from a thermophilic Geobacillus mahadii Geo-05 was heterologously expressed in Escherichia coli (E. coli) and characterized. The optimum temperature of BgcGC was at 60°C and stable from 20-60°C while optimum pH was at 6 and stable from pH 4-10. BgcGC showed high catalytic efficiency towards potato galactan (873.8 ml mg-1 s-1) and lupin galactan (1694.4 ml mg-1 s-1). The activity of BgcGC was not significantly affected with the presence of 100 mM K+, Tween-20 and 2-mercaptoethanol. Application of BgcGC towards pectin-containing galactan oligomer extracted from sweet potato peels resulted in galactose and GOS synthesis as revealed by high performance liquid chromatography analysis. Thus, this enzyme has a potential to be one of the enzyme candidates involves in pectin complex degradation to produce GOS.