Homodimeric β-galactosidase from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081: Expression in lactobacillus plantarum and biochemical characterization

Issue Date

2-2012

Abstract

The lacZ gene from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081, encoding a β-galactosidase of the glycoside hydrolase family GH2, was cloned into different inducible lactobacillal expression vectors for overexpression in the host strain Lactobacillus plantarum WCFS1. High expression levels were obtained in laboratory cultivations with yields of approximately 53000 U of β-galactosidase activity per liter of medium, which corresponds to ∼170 mg of recombinant protein per liter and β-galactosidase levels amounting to 63% of the total intracellular protein of the host organism. The wild-type (nontagged) and histidine-tagged recombinant enzymes were purified to electrophoretic homogeneity and further characterized. β-Galactosidase from L. bulgaricus was used for lactose conversion and showed very high transgalactosylation activity. The maximum yield of galacto-oligosaccharides (GalOS) was approximately 50% when using an initial concentration of 600 mM lactose, indicating that the enzyme can be of interest for the production of GalOS. © 2012 American Chemical Society.

Source or Periodical Title

Journal of Agricultural and Food Chemistry

ISSN

0021-8561

Volume

60

Issue

7

Page

1713-1721

Document Type

Article

Physical Description

tables, graphs

Language

English

Subject

β-galactosidase, galacto-oligosaccharides, lactase, prebiotics, transgalactosylation

Identifier

doi:10.1021/jf203909e.

Digital Copy

yes

Link to Full Text

Share

COinS