BioChem - DOS

Homodimeric β-Galactosidase from Lactobacillus delbrueckii subsp. bulgaricus DSM 20081: Expression in Lactobacillus plantarum and Biochemical Characterization

Journal of agricultural and food chemistry

Nguyen, Tien-Thanh; Nguyen, Hoang Anh; Arreola, Sheryl Lozel; Mlynek, Georg; Djinović -Carugo, Kristina; Mathiesen, Geir; Nguyen, Thu-Ha; Haltrich, Dietmar

<P/><P>The <I>lacZ</I> gene from <I>Lactobacillus delbrueckii</I><I/> subsp. <I>bulgaricus</I> DSM 20081, encoding a &beta;-galactosidase of the glycoside hydrolase family GH2, was cloned into different inducible lactobacillal expression vectors for overexpression in the host strain <I>Lactobacillus plantarum</I> WCFS1. High expression levels were obtained in laboratory cultivations with yields of approximately 53000 U of &beta;-galactosidase activity per liter of medium, which corresponds to ∼170 mg of recombinant protein per liter and &beta;-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. &beta;-Galactosidase from <I>L. bulgaricus</I> 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.</P>

2012

American Chemical Society

0021-8561

1520-5118

60

7

pp.1713-1721

10.1021/jf203909e

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART58876179

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