Characterization of the cross-linked enzyme aggregates of a novel β-galactosidase, a potential catalyst for the synthesis of galacto-oligosaccharides.

A novel β-galactosidase (Bgal1-3) was isolated from a marine metagenomic library and then its cross-linked enzyme aggregates (CLEAs) were prepared. The enzymatic properties of Bgal1-3-CLEAs were studied and compared with that of the free enzyme. The thermostability and storage stability of Bgal1-3 were significantly improved after it was immobilized as CLEAs.

Identification and characterization of an unusual glycosyltransferase-like enzyme with β-galactosidase activity from a soil metagenomic library.

Glycosyltransferases and glycoside hydrolases are two diversified groups of carbohydrate-active enzymes (CAZymes) in existence, they serve to build and break down the glycosidic bonds, respectively, and both categories have formed many sequence-based families. In this study, a novel gene (glyt110) conferring β-galactosidase activity was obtained from a metagenomic library of Turpan Basin soil. Sequence analysis revealed that glyt110 encoded a protein of 369 amino acids that, rather than belonging to a family typically known for β-galactosidase activity, belonged to glycosyltransferase family 4.

Enzymatic synthesis of galacto-oligosaccharides in an organic-aqueous biphasic system by a novel β-galactosidase from a metagenomic library.

Prebiotic galacto-oligosaccharides (GOS) were effectively synthesized from lactose in organic-aqueous biphasic media by a novel metagenome-derived β-galactosidase BgaP412. A maximum GOS yield of 46.6% (w/w) was achieved with 75.